Eduovisual
Gastrointestinal
Anorectal disorders: hemorrhoids, fissures, abscess, fistula
— Anorectal complaints account for ~4% of primary care visits; vastly underreported due to embarrassment
— Four core entities dominate Step 3: hemorrhoids, anal fissure, perianal abscess, anorectal fistula
— All share overlapping symptoms (pain, bleeding, drainage, mass) but diverge sharply in management
— Above dentate: visceral innervation → painless; columnar/transitional epithelium → internal hemorrhoids
— Below dentate: somatic (inferior rectal nerve) → exquisitely painful; squamous epithelium → fissures, external hemorrhoids, abscesses
— Lymphatic drainage: above → internal iliac; below → inguinal nodes (relevant for anal cancer staging)
— Painless bright red blood on toilet paper/coating stool → internal hemorrhoids
— Severe pain with defecation + streak of blood ("knife/glass") → anal fissure
— Throbbing perianal pain, fever, fluctuant mass → perianal abscess
— Chronic intermittent purulent/bloody drainage from perianal opening → fistula-in-ano (often post-abscess)
— Constipation, straining, low-fiber diet, pregnancy → hemorrhoids and fissures
— Crohn disease → atypical/lateral fissures, complex fistulas, recurrent abscesses
— Immunocompromise (HIV, diabetes, neutropenia) → severe/necrotizing perianal infection
— Receptive anal intercourse → consider STI proctitis, HPV, anal cancer
— Outpatient: most hemorrhoids and fissures managed conservatively before referral
— Inpatient/ED: abscess requires prompt I&D, not antibiotics alone
— Always consider malignancy in patients >40 with rectal bleeding — bleeding is not "just hemorrhoids" until colon evaluated
Board pearl: Never attribute rectal bleeding to hemorrhoids in a patient ≥45 (or with red flags) without colonoscopy to exclude colorectal neoplasia.
— Internal (above dentate): painless bright red bleeding, mucus discharge, prolapse, pruritus; pain only if thrombosed or strangulated
— Grading: I no prolapse; II prolapse, spontaneous reduction; III manual reduction; IV irreducible
— External (below dentate): perianal lump; acute thrombosis → sudden severe pain, bluish tender nodule
— Triggers: chronic straining, prolonged sitting, pregnancy/childbirth, heavy lifting, portal hypertension (rare cause)
— Classic stem: "tearing/knife-like pain during defecation lasting hours, with a streak of bright red blood on tissue"
— Patient may fear/avoid defecation → worsening constipation cycle
— Posterior midline (90%) in men, posterior or anterior midline in women (postpartum)
— Off-midline (lateral) or multiple fissures → think Crohn, TB, HIV, syphilis, leukemia, anal cancer
— Constant throbbing perianal pain worsening over days, not triggered solely by defecation
— Fever, chills, malaise; difficulty sitting; may report spontaneous drainage with sudden relief
— Cryptoglandular origin (~90%) — infected anal gland at dentate line
— Subtypes: perianal (most common, superficial), ischiorectal, intersphincteric, supralevator
— Chronic intermittent drainage (purulent, bloody, fecal) from external perianal opening
— History of prior abscess that "never fully healed" in ~50%
— Recurrent abscess at same site is fistula until proven otherwise
— Multiple/complex/high fistulas → Crohn disease workup
— Weight loss, anemia, change in stool caliber, family history CRC → colonoscopy
— Diarrhea, oral ulcers, joint/eye/skin disease → IBD
— Immunosuppression, anoreceptive intercourse, HIV status
Key distinction: Pain with defecation → fissure; constant pain → abscess; painless bleeding → internal hemorrhoid; chronic drainage → fistula.
— Left lateral (Sims) position, good lighting, chaperone, gentle gluteal retraction
— Sequence: inspection → palpation → digital rectal exam (DRE) → anoscopy/proctoscopy (if tolerated)
— Defer DRE/anoscopy in suspected acute fissure — too painful; diagnosis is clinical
— External: visible perianal skin tags or tense, purple, tender thrombosed nodule at anal verge
— Internal: typically not palpable on DRE (soft, collapse under pressure); seen on anoscopy at 3, 7, 11 o'clock (lithotomy)
— Have patient Valsalva to demonstrate prolapse and grade
— Gentle separation of buttocks reveals linear tear in anoderm, usually posterior midline
— Chronic fissure triad: (1) fissure with exposed internal sphincter fibers, (2) sentinel skin tag distally, (3) hypertrophied anal papilla proximally
— Severe sphincter spasm and pain → avoid forced DRE
— Erythema, induration, fluctuance, warmth at perianal skin (superficial perianal abscess)
— Ischiorectal: deep buttock pain, less obvious external findings; induration on DRE
— Intersphincteric/supralevator: external exam may be normal; severe pain on DRE → high suspicion, image
— Fever, tachycardia, leukocytosis → systemic involvement
— External opening: small papule with granulation tissue and drainage
— Palpable cord toward anus; expressing pus from external opening
— Goodsall rule: external opening anterior to transverse anal line → straight radial tract to anus; posterior opening → curved tract to posterior midline internal opening
— Vitals essential in suspected abscess — fever, tachycardia, hypotension
— In diabetics/immunocompromised: assess for necrotizing infection (crepitus, dishwater drainage, pain out of proportion) → surgical emergency
CCS pearl: For severe perianal pain with normal external exam, order pelvic MRI or exam under anesthesia (EUA) — don't miss a deep abscess.
— Hemorrhoids, fissures, simple perianal abscess, and simple fistula need no labs in otherwise healthy patients
— Labs/imaging are reserved for systemic illness, immunocompromise, atypical features, or preop planning
— CBC: anemia from chronic hemorrhoidal bleeding (microcytic, iron-deficiency pattern); leukocytosis with abscess
— BMP, glucose, HbA1c: undiagnosed diabetes in recurrent abscess is classic Step 3 stem
— HIV testing: recurrent or atypical perianal infection, complex fistula, ulcers, condyloma
— Coagulation studies only if on anticoagulants or bleeding suspected coagulopathic
— CRP/ESR: nonspecific, useful in suspected Crohn or deep abscess monitoring
— Type & screen prior to operative hemorrhoidectomy with bleeding
— Stool occult blood is not how you distinguish hemorrhoids from cancer — go to colonoscopy
— Stool cultures, C. difficile, ova/parasites if diarrhea-predominant proctitis
— STI testing (gonorrhea, chlamydia NAAT — rectal swab; syphilis RPR; HSV PCR) for proctitis or atypical ulcers
— Office bedside tool of choice for internal hemorrhoid evaluation and banding planning
— Visualizes distal 5–8 cm of anal canal
— Avoid in acute fissure (pain)
— Useful when distal source unclear, for proctitis, or to exclude distal rectal pathology
— Any rectal bleeding ≥45 years (USPSTF screening age)
— <45 with: family hx CRC, iron-deficiency anemia, weight loss, change in bowel habits, IBD features, persistent bleeding despite treatment
— Bleeding not clearly originating from a visualized hemorrhoid/fissure
— Generally not needed for outpatient hemorrhoids/fissures
— CT pelvis with contrast for suspected deep abscess, sepsis, or necrotizing infection in ED setting
Board pearl: "Rectal bleeding in a 55-year-old, hemorrhoids on anoscopy" — next step is still colonoscopy, not banding.
— Indication: complex/recurrent fistula, suspected Crohn perianal disease, deep/horseshoe abscess, supralevator extension
— Defines tract relative to sphincter complex; classifies per Parks: intersphincteric, transsphincteric, suprasphincteric, extrasphincteric
— Preoperative roadmap to preserve continence
— Alternative to MRI for fistula mapping and sphincter integrity (useful pre-sphincterotomy in women with prior obstetric injury)
— Hydrogen peroxide injection through external opening enhances tract visualization
— Both diagnostic and therapeutic
— Indicated when pain precludes office exam, for fistula tract probing, abscess drainage, biopsy of suspicious lesions
— Considered before lateral internal sphincterotomy in patients at risk for incontinence (multiparous women, prior anorectal surgery, elderly)
— Documents resting and squeeze pressures
— Mandatory for any nonhealing ulcer, mass, atypical fissure (off-midline, multiple), or pigmented/indurated lesion → exclude squamous cell carcinoma, melanoma, Crohn, syphilis, TB
— Send for histology and culture (AFB, fungal) as indicated
— Crohn workup: colonoscopy with ileal intubation + biopsies, MRE, fecal calprotectin
— HIV/STI panel: complex/recurrent perianal sepsis
— Diabetes screen: recurrent abscess
— Anal Pap/HPV testing: HIV+ MSM, immunosuppressed, history of HPV-related disease
— First-time simple perianal abscess in healthy adult → drainage alone, no imaging
— Classic posterior midline fissure in young patient → trial conservative therapy first
— Cardiac and bleeding risk assessment before hemorrhoidectomy or complex fistula surgery
— Hold anticoagulants per guideline (bridging if high thrombotic risk)
Step 3 management: Recurrent perianal abscess or multiple/complex fistulas in a young patient → send for colonoscopy and consider MRI pelvis to evaluate for Crohn disease before definitive surgery.
— Grades I–II and external (non-thrombosed): conservative — fiber 25–35 g/day, fluids ≥2 L, sitz baths, avoid prolonged toilet sitting, topical agents
— Grade II refractory, III: office-based procedures — rubber band ligation (first-line), sclerotherapy, infrared coagulation
— Grade IV, mixed internal/external, strangulated: excisional hemorrhoidectomy
— Acute thrombosed external hemorrhoid <72 h with severe pain: excision under local anesthesia (not just incision — high recurrence)
— >72 h or improving: conservative (sitz baths, analgesia, stool softeners) — pain resolves as clot organizes
— Acute (<6–8 weeks): conservative therapy heals >80%
· Fiber, fluids, sitz baths, topical analgesics (lidocaine)
· Add topical nifedipine or diltiazem (preferred over nitroglycerin — fewer headaches)
— Chronic (>6–8 weeks) or refractory:
· Continue topical CCB ± botulinum toxin injection into internal sphincter
· Definitive: lateral internal sphincterotomy (LIS) — highest cure rate; risk of incontinence (~5–10%)
· Avoid LIS in women with obstetric injury, elderly, IBD → use botulinum or fissurectomy/advancement flap
— Incision and drainage is definitive — bedside or OR; do not rely on antibiotics alone
— Antibiotics adjunctive only if: cellulitis, systemic signs, immunocompromise, diabetes, valvular heart disease, prosthetic material
— Simple, low (subcutaneous, low transsphincteric): fistulotomy
— Complex, high, anterior in women, Crohn-related: seton placement (cutting or draining), LIFT, advancement flap, fibrin glue/plug
— Crohn fistula: medical optimization (anti-TNF) + draining seton; avoid fistulotomy
— Sepsis, necrotizing infection, supralevator abscess, immunocompromise → OR + IV antibiotics + imaging
Board pearl: Antibiotics do not replace drainage for perianal abscess — this is among the most tested concepts.
— Psyllium 1 tbsp daily–BID; titrate up; pair with 2 L water
— Docusate 100 mg BID — softener, modest evidence
— Polyethylene glycol 17 g daily for refractory constipation
— Avoid stimulant laxatives chronically (bisacodyl, senna) — short-term rescue only
— Hydrocortisone 1–2.5% ointment BID × ≤7 days — itch and inflammation; do not use >1 week (skin atrophy)
— Topical anesthetics (lidocaine 5%) — symptomatic
— Witch hazel pads — astringent, soothing
— Phenylephrine-containing preparations — vasoconstriction; caution in hypertension/cardiac disease
— Topical nifedipine 0.2–0.3% or diltiazem 2% ointment TID × 6–8 weeks → healing ~65–95%; fewer headaches than nitrates
— Topical nitroglycerin 0.2–0.4% ointment TID — effective but headache in ~30%, tachyphylaxis; avoid with PDE5 inhibitors
— Botulinum toxin 20–30 U injected into internal sphincter — second-line; healing ~60–80%; transient incontinence
— Mechanism: all reduce internal anal sphincter tone, improving perfusion to ischemic fissure
— Acetaminophen scheduled + topical anesthetic; NSAIDs if not contraindicated
— Avoid opioids — worsen constipation; if needed short-term, pair with aggressive bowel regimen
— Adjunct (not substitute) for I&D when: cellulitis, systemic signs, immunosuppression, diabetes, valvular disease/prosthesis, neutropenia
— Empiric coverage: amoxicillin-clavulanate PO, or ciprofloxacin + metronidazole; inpatient: piperacillin-tazobactam or ceftriaxone + metronidazole
— Necrotizing infection: broad-spectrum + clindamycin (toxin suppression) + emergent debridement
— Flavonoids (micronized purified flavonoid fraction) — used internationally for hemorrhoidal symptoms; limited US availability, not standard of care
Key distinction: Topical CCBs > nitrates for fissures because of headache profile — preferred first-line on Step 3.
— Rubber band ligation (RBL) — first-line for grades I–III internal hemorrhoids
· Band placed above dentate line (avoid pain); 1–3 sessions
· Complications: pain, bleeding (delayed 7–10 days as band falls off), pelvic sepsis (rare, life-threatening — fever, urinary retention, severe pain → ED, broad antibiotics, OR)
· Contraindication: anticoagulation (relative), immunocompromise
— Sclerotherapy (5% phenol in oil): small grade I–II; useful on anticoagulants
— Infrared coagulation: grade I–II
— Excisional (Milligan-Morgan/Ferguson) — grade IV, large mixed, strangulated, failed office therapy
— Most effective, most painful recovery; expect 2–4 weeks
— Stapled hemorrhoidopexy — less pain, higher recurrence; avoid in external component
— Doppler-guided hemorrhoidal artery ligation (HAL) — newer, less painful, moderate efficacy
— <72 h + severe pain: elliptical excision (not just incision) under local
— >72 h or mild: conservative
— Lateral internal sphincterotomy (LIS) — gold standard for chronic fissure refractory to medical therapy; >90% healing
— Risk: fecal incontinence (flatus most common); screen with manometry/EAUS in high-risk patients
— Fissurectomy + advancement flap: continence-sparing alternative
— Botulinum toxin: temporary "chemical sphincterotomy"
— Bedside I&D for superficial perianal abscess under local
— Cruciate or elliptical incision close to anal verge to minimize future fistula tract length
— Pack loosely; sitz baths starting POD#1; no routine packing changes in deeper pocket — consider drain
— Ischiorectal/intersphincteric/supralevator: OR drainage, often with imaging
— Fistulotomy: simple low fistulas (<1/3 sphincter)
— Seton: high/complex, Crohn — drains and matures tract
— LIFT (ligation of intersphincteric fistula tract), endorectal advancement flap, fibrin glue/plug: sphincter-preserving
CCS pearl: Post-banding patient returns with fever + urinary retention + severe pelvic pain → admit, broad-spectrum IV antibiotics, urgent surgical evaluation for pelvic sepsis.
— Baseline sphincter weakness, multiparity, prior surgery → avoid lateral internal sphincterotomy when possible; use botulinum toxin or advancement flap
— Document baseline continence carefully; obtain anal manometry/EAUS preoperatively
— Polypharmacy: many anticholinergics, opioids, CCBs worsen constipation — review and deprescribe
— Higher rate of underlying malignancy: low threshold for colonoscopy for any rectal bleeding
— Falls risk after sedation/regional anesthesia; same-day discharge planning critical
— Office banding: hold antiplatelets/anticoagulants per procedure-specific bleeding risk; resume early
— Hemorrhoidectomy: hold warfarin 5 days, DOACs 48 h, ASA may be continued for cardiac indication if low bleeding risk
— Bridging: only for mechanical valve, recent VTE, AF with very high CHA₂DS₂-VASc
— Restart timing balances rebleeding (7–10 days post-banding) with thrombotic risk
— Avoid NSAIDs (AKI, GI bleed risk)
— Avoid magnesium-containing laxatives (hypermagnesemia); use PEG, lactulose with caution
— Adjust ciprofloxacin dose in CrCl <50; levofloxacin likewise
— Phosphate-containing enemas → acute phosphate nephropathy in CKD/elderly — contraindicated
— Hemorrhoids in cirrhotics are usually not from portal hypertension — most are routine; anorectal varices are a distinct entity (engorged veins crossing dentate line, communicating with portosystemic circulation)
— Do NOT band varices — use suture ligation or address portal hypertension (TIPS) for bleeding varices
— Coagulopathy: correct INR cautiously; thrombocytopenia <50k → platelet transfusion or thrombopoietin agonist pre-op
— Avoid acetaminophen >2 g/day in advanced cirrhosis; avoid NSAIDs entirely
— Recurrent or severe perianal abscess → screen for and tightly control diabetes (HbA1c)
— Higher risk of necrotizing perianal infection (Fournier gangrene) — emergent broad-spectrum antibiotics + surgical debridement
— Optimize glycemia perioperatively (target 140–180 mg/dL)
Step 3 management: Cirrhotic with rectal bleeding — distinguish hemorrhoids vs. anorectal varices on anoscopy; varices require portal pressure reduction, not banding.
— Hemorrhoids and fissures are extremely common (constipation, progesterone-mediated venous distension, fetal pressure, straining at delivery)
— First-line: fiber, fluids, sitz baths, topical lidocaine, witch hazel; acetaminophen for pain
— Safe topicals: hydrocortisone 1% short course (category C, low absorption); topical lidocaine
— Avoid: nitroglycerin (hypotension/headache), systemic NSAIDs (especially 3rd trimester — premature ductus closure)
— Topical nifedipine/diltiazem for fissure: limited safety data; use after risk-benefit discussion, generally acceptable
— Procedures: defer to postpartum when possible; thrombosed external hemorrhoid can be excised under local if severe
— Postpartum fissure (often anterior midline) usually heals with conservative care
— Hemorrhoids are rare in children — if present, evaluate for portal hypertension (biliary atresia, cirrhosis) or anorectal varices
— Anal fissure is the most common cause of bright red blood per rectum in infants/toddlers — from hard stools; treat with stool softeners (PEG), increased fluids, sitz baths
— Recurrent perianal abscess/fistula in infant boys <2 years: cryptoglandular, often heals spontaneously with conservative care; avoid aggressive surgery
— Atypical fistulas, multiple abscesses in older child → workup for Crohn disease, immunodeficiency (CGD), HIV
— Atypical, multiple, or non-healing ulcers → biopsy for HSV, CMV, syphilis, anal SCC, lymphoma
— Neutropenic patients with perianal pain: avoid I&D when ANC <500 if no fluctuance — risk of bacteremia; treat with broad antibiotics, drain when neutrophils recover (case-by-case)
— Higher anal cancer risk (HPV) — anal Pap, HRA screening per local protocol
— Crohn perianal disease: complex fistulas, deep ulcers, skin tags ("elephant ears")
— Management: anti-TNF (infliximab, adalimumab) + draining seton; avoid fistulotomy
— UC: perianal disease uncommon — if present, reconsider Crohn diagnosis
— Screen for STI proctitis (GC, CT including LGV, syphilis, HSV), HPV-related disease
— Anal cancer screening in HIV+ MSM
Board pearl: A 1-year-old boy with recurrent perianal fistula and otherwise normal exam — conservative management; most resolve spontaneously without surgery.
— Thrombosis — acute severe pain, palpable purple nodule
— Strangulation — irreducible prolapsed grade IV with vascular compromise; surgical emergency
— Chronic bleeding → iron-deficiency anemia (work up other GI sources first!)
— Skin tags — cosmetic, hygiene difficulty after thrombosis resolves
— Post-banding: delayed hemorrhage (7–10 days), pelvic sepsis (rare, lethal — triad: fever, urinary retention, perineal pain), urinary retention
— Post-hemorrhoidectomy: pain, anal stenosis, urinary retention, incontinence (rare)
— Chronicity with sentinel tag and hypertrophied papilla
— Recurrent infection → perianal abscess/fistula at fissure base
— Post-LIS: incontinence to flatus (~5–10%), liquid stool (lower), solid (rare)
— Keyhole deformity → soiling
— Fistula formation in 30–50% even after appropriate drainage
— Recurrence of abscess
— Fournier gangrene — necrotizing infection of perineum; risk factors: diabetes, immunocompromise, alcoholism; mortality 20–40%
— Pelvic sepsis from supralevator extension
— Bacteremia — endocarditis risk in valvular disease/prosthesis
— Recurrence after surgery (10–30%)
— Fecal incontinence if excessive sphincter division
— Malignant transformation in chronic fistula (rare, decades-long) — mucinous adenocarcinoma
— Persistent drainage, skin maceration, psychosocial distress
— Missed colorectal cancer mistaken for hemorrhoidal bleeding — devastating Step 3 error
— Missed anal SCC in chronic "fissure" or "fistula" — biopsy nonhealing lesions
— Missed Crohn delaying medical therapy and worsening perianal destruction
— Spinal/regional: urinary retention, headache
— Local injection: vasovagal, lidocaine toxicity at high doses
Key distinction: Fever + urinary retention + perianal pain after recent hemorrhoid banding = pelvic sepsis — emergency admission, IV antibiotics, surgical consult.
— Uncomplicated hemorrhoids grade I–III
— Acute or chronic anal fissure without abscess
— Simple perianal abscess in immunocompetent adult with bedside I&D and reliable follow-up
— Stable chronic fistula awaiting elective surgery
— Thrombosed external hemorrhoid <72 h with severe pain — excision
— Strangulated grade IV hemorrhoid
— Suspected ischiorectal, intersphincteric, or supralevator abscess
— Suspected fistula requiring evaluation
— Failed conservative management of fissure → consider botulinum or LIS
— Sepsis: fever, tachycardia, hypotension, leukocytosis
— Necrotizing perianal infection (Fournier) — crepitus, dishwater drainage, pain disproportionate to exam, rapid spread → surgical emergency
— Immunocompromised patient with perianal pain, even without fluctuance
— Neutropenic patient with perianal infection (ANC <500)
— Significant hemorrhoidal bleeding causing hemodynamic instability or symptomatic anemia
— Inability to control pain or void (urinary retention common post-procedure)
— Septic shock from anorectal source
— Fournier gangrene with hemodynamic instability or large debridement
— Major perioperative complications
— Colorectal surgery: complex fistula, recurrent disease, sphincter-sparing planning
— Gastroenterology: rule out IBD, colonoscopy for bleeding work-up, Crohn perianal medical optimization
— Infectious disease: complex/recurrent infection, HIV-positive patient, necrotizing infection
— Wound care: post-Fournier reconstruction, large open wounds
— IV access × 2, IVF resuscitation, NPO
— CBC, BMP, lactate, blood cultures × 2, type & screen
— IV piperacillin-tazobactam (or ceftriaxone + metronidazole)
— CT pelvis with contrast
— Urgent surgery consult for OR I&D
— Diabetes screen (HbA1c), HIV test if not recent
— Tetanus per status
Step 3 management: Diabetic patient with severe perineal pain out of proportion, crepitus, hypotension → resuscitate, broad antibiotics, emergent surgical debridement — do not delay for imaging.
— Internal hemorrhoid: painless bleeding, prolapse, no fever
— External hemorrhoid (thrombosed): acute painful purple nodule at anal verge
— Anal fissure: sharp pain with defecation, visible tear posterior midline
— Perianal abscess: constant throbbing pain, fluctuant tender mass, fever
— Anorectal fistula: chronic intermittent drainage, external opening with granulation
— Pruritus ani: itching without bleeding/mass; idiopathic vs. hygiene, fungal, contact dermatitis, pinworm
— Rectal prolapse: full-thickness rectum protrudes, concentric rings (vs. hemorrhoid radial folds); elderly multiparous women
— Solitary rectal ulcer syndrome: straining, mucus, bleeding; anterior rectal ulcer; treat constipation
— Proctalgia fugax: brief (seconds–minutes) severe rectal pain, normal exam
— Levator ani syndrome: chronic dull rectal pain, levator tenderness on DRE; treat with biofeedback, muscle relaxants
— Coccygodynia: pain localized to coccyx, worse with sitting
— Anal stenosis: post-surgical or chronic fissure; narrowing → constipation, pain
— Anal skin tags: residual from thrombosed external hemorrhoid; usually cosmetic
— Condyloma acuminatum (HPV): cauliflower lesions; treat with topical/surgical removal; biopsy if atypical
— Pilonidal disease: midline pits over coccyx (above anus, not perianal); abscess, sinus
— Hidradenitis suppurativa: chronic recurrent perianal/perineal abscesses with sinus tracts; apocrine origin
— Anal squamous cell carcinoma: HPV-related, ulcer or mass; biopsy any nonhealing lesion; treat with Nigro protocol (5-FU + mitomycin + radiation)
— Rectal adenocarcinoma: bleeding, change in bowel habits, mass on DRE; colonoscopy + biopsy + MRI rectum
— Anal melanoma: pigmented mass, poor prognosis
— Mucinous adenocarcinoma in chronic fistula: decades-old fistula with new mass
— Gonorrhea, chlamydia (incl. LGV), syphilis, HSV, CMV (immunocompromised)
— Present with anorectal pain, discharge, tenesmus, bleeding
— NAAT, serology, culture; empiric ceftriaxone + doxycycline if STI suspected
Key distinction: Concentric mucosal rings = rectal prolapse; radial folds with cushions = prolapsing hemorrhoids — frequently tested image-recognition pair.
— Atypical fissures (lateral, multiple, deep), complex/recurrent fistulas, deep ulcers, skin tags
— Workup: colonoscopy with biopsies, MRE/MRI pelvis, fecal calprotectin
— Treatment: anti-TNF + draining seton; avoid aggressive sphincter surgery
— Bloody diarrhea, mucus, tenesmus; rectum always involved; perianal disease uncommon — if present, reconsider Crohn
— Leukemia/neutropenia → atypical perianal infection, deep ulcers
— Coagulopathy/anticoagulation → exaggerated hemorrhoidal bleeding
— Sickle cell → priapism mimicker (not anorectal but groin pain DDx)
— HIV: aggressive anal SCC, atypical ulcers, complex fistulas, opportunistic infections
— TB: chronic perianal fistula with caseating granulomas
— Syphilis: painless chancre at anus; condyloma lata
— HSV: clustered painful vesicles/ulcers, especially in immunosuppressed
— LGV chlamydia: severe proctitis, bloody discharge, lymphadenopathy in MSM
— Diabetes: recurrent abscess, slow healing, Fournier gangrene risk
— Hypothyroidism: chronic constipation worsening hemorrhoids/fissures
— Endometriosis on rectovaginal septum: cyclic rectal pain, dyschezia, bleeding
— Bartholin/vulvar abscess: differentiate by location anterior to anus
— Prostatitis: perineal pain, urinary symptoms; tender prostate on DRE
— Fournier gangrene: scrotal/perineal involvement; necrotic skin, crepitus
— Functional anorectal pain (proctalgia fugax, levator ani): exclude structural causes first
— Anismus/pelvic floor dyssynergia: paradoxical contraction → constipation, pain; treat with biofeedback
— Opioids, anticholinergics, iron, calcium supplements → constipation → hemorrhoids/fissures
— Chemotherapy (especially with neutropenia) → mucositis, perianal infection
— Portal hypertension → anorectal varices (not hemorrhoids); manage by reducing portal pressure (TIPS, suture ligation)
Board pearl: Lateral or multiple anal fissures, deep "elephant-ear" skin tags, or complex recurrent fistula in a young patient → rule out Crohn disease before any surgery.
— Fiber 25–35 g/day via diet + psyllium; titrate gradually to avoid bloating
— Fluid 2 L/day
— Avoid straining — don't sit on toilet >5 minutes; respond to urge promptly
— Squatty Potty / footstool: anorectal angle straightening reduces strain
— No reading/phone on toilet — prolonged sitting increases venous engorgement
— Gentle hygiene: water rinse or unscented wipes; pat dry; avoid harsh soaps
— Regular exercise — improves transit
— Sitz baths 2–3×/day × 1–2 weeks
— Stool softeners (docusate) + osmotic laxative (PEG) × 2–4 weeks
— Acetaminophen scheduled; topical lidocaine; minimize opioids (constipation)
— Return precautions: heavy bleeding, fever, urinary retention, severe pain (pelvic sepsis)
— Resume normal diet; activity restrictions per procedure
— Continue fiber and softener indefinitely — recurrence is common with constipation relapse
— Complete full 6–8 week course of topical CCB even if symptoms improve early
— Sitz baths starting POD#1
— Daily wound check, gentle irrigation
— Stool softeners
— Schedule follow-up at 2–3 weeks to assess for fistula formation
— Counsel: ~30–50% develop fistula even with optimal care — not a treatment failure
— Sitz baths, wound packing if applicable
— Seton care: keep clean, expect ongoing drainage; periodic seton change
— Crohn patients: continue anti-TNF therapy indefinitely; coordinate with GI
— Colonoscopy for any patient ≥45 with rectal bleeding, or earlier with risk factors — don't anchor on hemorrhoids
— Anal Pap/HRA in high-risk groups (HIV+ MSM, immunosuppressed transplant patients) per current guidelines
— HPV vaccination for eligible patients (through age 26 routine, shared decision 27–45)
— Weight management, smoking cessation (improves wound healing)
— Treat OSA — straining at stool worse with poor sleep/obesity
— Counsel on safe sexual practices if STI risk
Step 3 management: Most hemorrhoid and fissure recurrences are bowel-habit relapses — long-term fiber and hydration are the single most effective preventive intervention.
— Hemorrhoids (conservative): 4–6 weeks to assess response; if persistent → office procedure or referral
— Post-banding: routine f/u 2–4 weeks; sooner if symptoms; may need repeat banding for next cushion at 4–6 week intervals
— Post-hemorrhoidectomy: 2–3 weeks for wound check, anal stenosis screen, continence assessment
— Anal fissure: 6–8 weeks on topical therapy → assess healing; persistent → escalate (botulinum, LIS)
— Perianal abscess post-I&D: 2–3 weeks to assess healing and detect fistula formation; then 6–8 weeks
— Fistula post-op: 2–4 weeks for wound assessment, then every 3 months × 1 year; seton patients followed long-term
— Symptom diary: pain scores, bleeding frequency, bowel habits
— CBC if chronic bleeding — recheck after intervention; correct iron deficiency with oral or IV iron
— Continence assessment after sphincter surgery (Wexner score; ask about flatus, liquid, solid leakage)
— Wound healing photo or in-person check
— Crohn patients: fecal calprotectin, CRP, MRI pelvis annually for perianal disease
— Set realistic expectations: hemorrhoidectomy recovery is 2–4 weeks of significant pain
— Banding may require multiple sessions
— Even with optimal abscess drainage, 30–50% develop a fistula — schedule follow-up
— Fissure healing requires 6–8 weeks; don't abandon therapy early
— Recurrence is common without sustained bowel-habit changes
— Anorectal disease causes embarrassment, social withdrawal, sexual dysfunction
— Screen for depression/anxiety, especially with chronic Crohn fistulas
— Pelvic floor physical therapy for chronic pain, dyssynergia, post-surgical continence issues
— Heavy bleeding, fever >38.5°C, severe escalating pain, urinary retention, inability to tolerate oral intake
— Spreading erythema, foul drainage, systemic symptoms
— Coordinate handoff between ED → primary care → colorectal surgery
— Closed-loop communication for pending biopsy results and colonoscopy referrals — common safety gap
CCS pearl: Always schedule and document the 2–3 week follow-up after perianal abscess drainage — missed fistula detection is a leading cause of recurrent presentation.
— Disclose specific risks: fecal incontinence (especially LIS, fistulotomy), recurrence, bleeding, infection, anal stenosis, sexual dysfunction
— For LIS in women with obstetric injury or prior anorectal surgery, document discussion of higher incontinence risk and consideration of sphincter-sparing alternatives
— Use teach-back: patient repeats risks in own words
— Anorectal exams are uniquely embarrassing; offer chaperone (required by many institutional policies), warm room, drapes, clear narration of each step
— In patients with history of sexual abuse, explicitly ask permission before each step and accept refusal; defer DRE/anoscopy if not essential
— Document chaperone presence
— Pediatric anorectal trauma, recurrent unexplained injury, or sexually transmitted infection in prepubertal child → mandatory child abuse reporting
— Forensic evidence collection if acute assault; involve specialized examiners (SANE)
— Elder/dependent adult abuse with anorectal injury → mandatory reporting per state law
— Missed follow-up after presumed "hemorrhoidal bleeding" without colonoscopy referral → delayed colorectal cancer diagnosis is a high-frequency malpractice scenario
— Closed-loop communication: ensure colonoscopy is scheduled, completed, results reviewed, and patient notified — document each step
— Post-discharge from ED after abscess drainage: ensure surgical follow-up arranged before discharge
— Failure to restart anticoagulation after hemorrhoid surgery → thromboembolism
— Restarting too early → rebleeding from banding site
— Use structured perioperative plan with primary care and cardiology
— Avoid unnecessary antibiotics for simple drained abscess — overuse drives resistance and C. difficile
— Document specific indication (cellulitis, valvular disease, immunocompromise) when prescribing
— Disparities in colorectal cancer screening and timely diagnosis — Black patients have higher CRC mortality
— Insurance/access barriers to colonoscopy after rectal bleeding — facilitate financial counseling, FIT-based pathways where appropriate
— Language-concordant care and certified interpreters for sensitive exams
— Protect adolescent confidentiality per state law for STI evaluation and treatment
— Partner notification (expedited partner therapy where legal)
Board pearl: Documenting "colonoscopy scheduled, patient educated, follow-up confirmed" is both a quality measure and your best defense against the missed-CRC-after-hemorrhoid scenario.
— Dentate line separates pain-sensitive (below) from pain-insensitive (above)
— Internal hemorrhoid cushions at 3, 7, 11 o'clock (left lateral, right anterior, right posterior) in lithotomy
— Anal canal length ~4 cm; internal sphincter is involuntary (smooth muscle), external is voluntary (skeletal)
— Painless bright red bleeding + prolapse → internal hemorrhoid
— Painful defecation + posterior midline tear → anal fissure
— Fever + fluctuant perianal mass → perianal abscess
— Chronic drainage + perianal opening → fistula-in-ano
— Lateral or multiple fissures → Crohn, HIV, TB, leukemia
— Recurrent abscess + complex fistula → Crohn until proven otherwise
— Concentric mucosal rings prolapsing → rectal prolapse (not hemorrhoid)
— Fever, urinary retention, pelvic pain post-banding → pelvic sepsis
— Crepitus + necrosis + diabetes → Fournier gangrene
— Cirrhotic with rectal bleeding → consider anorectal varices
— Topical CCB > nitrate for fissure (less headache)
— Excise thrombosed external hemorrhoid only if <72 h and severe pain
— I&D > antibiotics for abscess
— Goodsall rule: anterior external opening → straight tract; posterior → curved to posterior midline
— Don't ligate anorectal varices — they communicate with portal system
— No fistulotomy in Crohn — use seton + anti-TNF
— LIS is gold-standard chronic fissure cure but risks incontinence
— Nifedipine 0.2–0.3% topical TID × 6–8 weeks
— Diltiazem 2% topical TID × 6–8 weeks
— Nitroglycerin 0.4% topical BID-TID (headache common)
— Botulinum 20–30 U into internal sphincter
— Hydrocortisone 1% topical ≤1 week
— Colonoscopy for any rectal bleeding ≥45
— HPV vaccination through age 26 routine
— Anal cancer screening in HIV+ MSM
— Fistula after abscess: 30–50%
— Cryptoglandular origin of abscesses: ~90%
— LIS healing rate: >90%; incontinence: 5–10%
— Banding sessions: 1–3 typical
— Pelvic sepsis post-banding: rare but lethal
Key distinction: "Painful anorectal bleeding" — think fissure or thrombosed hemorrhoid; "painless bleeding" — think internal hemorrhoid or cancer (always rule out malignancy).
— 35-yo with intermittent painless bright red blood on tissue, anoscopy shows prolapsing internal hemorrhoids reducing spontaneously
— Answer: high-fiber diet, fluids, sitz baths (grade II conservative)
— Twist: same patient at age 55 → next step is colonoscopy before banding
— 28-yo postpartum woman with severe tearing pain and streak of blood; posterior midline tear on exam
— Answer: topical nifedipine or diltiazem + fiber + sitz baths
— Twist: fissure is lateral → workup for Crohn
— 45-yo diabetic with 3 days of perianal pain, fever, fluctuant 4-cm mass
— Answer: incision and drainage (bedside); antibiotics adjunctive due to diabetes
— Twist: severe pain but normal external exam → MRI pelvis or EUA for deep abscess
— 30-yo with recurrent perianal pus drainage, history of prior abscess, external opening posterior
— Answer: surgical evaluation for fistulotomy; Goodsall rule for tract
— Twist: multiple complex fistulas, oral ulcers, diarrhea → Crohn workup, seton + anti-TNF
— 60-yo diabetic with severe perineal pain, crepitus, dishwater drainage, hypotension
— Answer: resuscitate, broad-spectrum IV antibiotics, emergent surgical debridement for Fournier gangrene
— Patient 5 days after rubber band ligation with fever, urinary retention, severe pelvic pain
— Answer: admit, IV antibiotics, surgical consult for pelvic sepsis
— 24-yo with sudden painful purple anal nodule
— <72 h, severe pain → excision under local
— >72 h or mild → conservative
— Cirrhotic with engorged anal veins extending above dentate
— Answer: anorectal varices, treat portal hypertension; do NOT band
— 18-month-old boy with recurrent small perianal fistula, otherwise healthy
— Answer: conservative management — most resolve spontaneously
— HIV+ patient with nonhealing perianal ulcer
— Answer: biopsy to exclude anal SCC, HSV, syphilis
— Symptomatic grade II hemorrhoids on chronic AC
— Answer: sclerotherapy preferred (lower bleeding risk than banding)
Step 3 management: When stem includes rectal bleeding + age ≥45, the answer almost always includes colonoscopy, even if hemorrhoids are visible.
Anorectal disease is a four-entity pattern game: painless bleeding = internal hemorrhoid, painful defecation = fissure, fluctuant febrile pain = abscess (drain it), chronic drainage = fistula — and rectal bleeding in anyone ≥45 demands colonoscopy regardless of what you see at the anus.
— Grade-driven care: I–II conservative, II–III banding, IV/strangulated/thrombosed <72 h → surgery
— Always rule out colorectal cancer in age-appropriate or red-flag bleeding
— Cirrhotic bleeding may be anorectal varices — do not band
— Posterior midline + sharp pain + streak of blood = classic
— Topical CCB (nifedipine/diltiazem) > nitrates; botulinum or LIS if refractory
— Lateral/multiple/atypical fissures → rule out Crohn, HIV, TB, malignancy
— LIS most effective but watch incontinence risk in women and elderly
— Drainage is the treatment — antibiotics are adjunct, not substitute
— Deep abscess (ischiorectal, supralevator) may have normal external exam → image or EUA
— 30–50% develop a fistula; schedule 2–3 week follow-up
— Diabetes/immunocompromise → Fournier gangrene risk; broad antibiotics + emergent debridement
— Goodsall rule predicts tract; classify by Parks
— Simple low → fistulotomy; complex/high/anterior in women → sphincter-sparing (seton, LIFT, flap)
— Crohn fistula → anti-TNF + draining seton, never primary fistulotomy
— Fiber 25–35 g, hydration, avoid straining, sitz baths, short toilet time
— Consent must address incontinence risk before sphincter surgery
— Document colonoscopy follow-up to avoid missed-cancer malpractice
Board pearl: Three reflexes win this topic — don't anticoagulate-band blindly, don't treat abscess with antibiotics alone, and don't call rectal bleeding hemorrhoids without a colonoscopy.