🩺 FCPS Paediatrics TOACS · Anal Fissure
📖 Nelson's Textbook of Pediatrics · Chronic constipation · Painful defecation · Sentinel tag · Medical management
📚 paeds.online – Paeds Online
🩺 OBSERVED/INTERACTIVE STATION · CPSP FORMAT · 8 MINUTES · PAINFUL DEFECATION + SENTINEL TAG → CHRONIC ANAL FISSURE
📋 Observed Station – “Child with chronic constipation, painful stool, sentinel tag”
👧🏻 Clinical Scenario (TOACS – read aloud / displayed):
A 4‑year‑old girl is brought by her mother with a 6‑month history of chronic constipation. She passes hard, large‑diameter stools every 3‑4 days, associated with severe pain during defecation. Mother reports occasional bright red blood on the surface of the stool and that the child often hides in a corner or crosses her legs to avoid passing stool (withholding behavior). On examination, gentle separation of the buttocks reveals a linear tear in the posterior midline with a small skin tag (sentinel tag) at the distal end. The anal opening is normally positioned.
🎯 Task (examiner observed): Recognize the findings as a chronic anal fissure secondary to functional constipation. Explain the pathophysiology (hard stool → mucosal tear → pain → withholding → harder stool → cycle). Outline management: disimpaction (if needed), stool softeners (PEG 3350), dietary modifications, sitz baths, and when to consider topical nifedipine/nitroglycerin. Discuss red flags (atypical location, multiple fissures, poor healing → suspect Crohn disease).
📸 Photograph of anal fissure with sentinel tag (posterior midline)
A 4‑year‑old girl is brought by her mother with a 6‑month history of chronic constipation. She passes hard, large‑diameter stools every 3‑4 days, associated with severe pain during defecation. Mother reports occasional bright red blood on the surface of the stool and that the child often hides in a corner or crosses her legs to avoid passing stool (withholding behavior). On examination, gentle separation of the buttocks reveals a linear tear in the posterior midline with a small skin tag (sentinel tag) at the distal end. The anal opening is normally positioned.
🎯 Task (examiner observed): Recognize the findings as a chronic anal fissure secondary to functional constipation. Explain the pathophysiology (hard stool → mucosal tear → pain → withholding → harder stool → cycle). Outline management: disimpaction (if needed), stool softeners (PEG 3350), dietary modifications, sitz baths, and when to consider topical nifedipine/nitroglycerin. Discuss red flags (atypical location, multiple fissures, poor healing → suspect Crohn disease).
📸 Photograph of anal fissure with sentinel tag (posterior midline)
Figure: Posterior midline anal fissure with sentinel tag – characteristic of chronic fissure secondary to constipation.
⚠️ CLINICAL PEARLS :
• Anal fissure = linear tear in the anal mucosa, usually posterior midline (90%).
• Classic presentation: painful defecation, bright red blood on stool surface, withholding behavior.
• Sentinel tag (hypertrophied anal papilla) indicates chronicity.
• Primary cause: constipation with passage of hard, large stools.
• Acute fissure: treat constipation (PEG 3350, fluids, fiber, sitz baths).
• Chronic fissure (>6 weeks): may require topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%).
• Surgery (internal sphincterotomy) rarely needed in children.
• Anal fissure = linear tear in the anal mucosa, usually posterior midline (90%).
• Classic presentation: painful defecation, bright red blood on stool surface, withholding behavior.
• Sentinel tag (hypertrophied anal papilla) indicates chronicity.
• Primary cause: constipation with passage of hard, large stools.
• Acute fissure: treat constipation (PEG 3350, fluids, fiber, sitz baths).
• Chronic fissure (>6 weeks): may require topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%).
• Surgery (internal sphincterotomy) rarely needed in children.
🧠 DIFFERENTIAL DIAGNOSIS:
• Juvenile polyp: painless rectal bleeding, no pain with defecation.
• Perianal abscess/fistula: painful fluctuant mass, purulent discharge.
• Hemorrhoids: rare in children, painless bleeding or thrombosed external hemorrhoid.
• Crohn disease: multiple fissures, lateral location, perianal skin tags, poor healing.
• Pinworms: perianal itching (worse at night), no bleeding.
• Juvenile polyp: painless rectal bleeding, no pain with defecation.
• Perianal abscess/fistula: painful fluctuant mass, purulent discharge.
• Hemorrhoids: rare in children, painless bleeding or thrombosed external hemorrhoid.
• Crohn disease: multiple fissures, lateral location, perianal skin tags, poor healing.
• Pinworms: perianal itching (worse at night), no bleeding.
💡 Examiner instruction (observed station): Candidate must (1) correctly diagnose chronic anal fissure, (2) explain the vicious cycle of constipation → fissure → withholding → harder stools, (3) outline stepwise management (disimpaction if needed → maintenance PEG → dietary changes → sitz baths), (4) mention topical therapies for chronic fissures, (5) discuss red flags for Crohn disease, and (6) reassure parents about excellent prognosis with medical management.
🔬 Diagnosis & Management Algorithm (Anal Fissure)
1 History
Painful defecation, bright red blood on stool surface, stool frequency/consistency, withholding behavior.
Painful defecation, bright red blood on stool surface, stool frequency/consistency, withholding behavior.
2 Physical exam
Gentle separation of buttocks: linear tear (usually posterior midline). Sentinel tag if chronic. Rectal exam if no contraindication (rule out impaction).
Gentle separation of buttocks: linear tear (usually posterior midline). Sentinel tag if chronic. Rectal exam if no contraindication (rule out impaction).
3 Acute fissure management
Treat constipation: PEG 3350 (0.5-1 g/kg/day), increase fluids/fiber, sitz baths (warm water 10 min after BM). Most heal within 1-2 weeks.
Treat constipation: PEG 3350 (0.5-1 g/kg/day), increase fluids/fiber, sitz baths (warm water 10 min after BM). Most heal within 1-2 weeks.
4 Chronic fissure (>6 weeks)
Add topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%) BID for 4-8 weeks. Botulinum toxin for refractory cases (rare).
Add topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%) BID for 4-8 weeks. Botulinum toxin for refractory cases (rare).
5 Red flags → evaluate for Crohn
Lateral or multiple fissures, perianal skin tags, oral ulcers, poor healing, weight loss, abdominal pain, diarrhea.
Lateral or multiple fissures, perianal skin tags, oral ulcers, poor healing, weight loss, abdominal pain, diarrhea.
6 Prevention
Maintain soft stools with balanced diet, adequate fluid intake, regular toileting.
Maintain soft stools with balanced diet, adequate fluid intake, regular toileting.
📋 INDICATIONS FOR REFERRAL (PEDIATRIC SURGERY/GASTROENTEROLOGY):
• Fissure not healing after 8-12 weeks of optimal medical therapy.
• Atypical location (anterior midline, lateral, multiple) – especially if associated with systemic symptoms.
• Recurrent fissures after healing.
• Severe pain refractory to topical therapy.
• Suspected Crohn disease (perianal disease, weight loss, extraintestinal manifestations).
• Need for botulinum toxin or sphincterotomy (extremely rare in children).
• Fissure not healing after 8-12 weeks of optimal medical therapy.
• Atypical location (anterior midline, lateral, multiple) – especially if associated with systemic symptoms.
• Recurrent fissures after healing.
• Severe pain refractory to topical therapy.
• Suspected Crohn disease (perianal disease, weight loss, extraintestinal manifestations).
• Need for botulinum toxin or sphincterotomy (extremely rare in children).
🩺 TOPICAL THERAPIES FOR CHRONIC FISSURE :
• Nifedipine 0.2-0.3% ointment: Apply BID to anal canal (inside). Causes smooth muscle relaxation → reduced anal sphincter pressure → improved healing. Fewer headaches than nitroglycerin.
• Nitroglycerin 0.2-0.4% ointment: Effective but headache common (30-60%).
• Botulinum toxin injection: Off‑label, used in refractory cases.
• Internal sphincterotomy: Rare in children; reserved for severe refractory cases due to risk of incontinence.
• Nifedipine 0.2-0.3% ointment: Apply BID to anal canal (inside). Causes smooth muscle relaxation → reduced anal sphincter pressure → improved healing. Fewer headaches than nitroglycerin.
• Nitroglycerin 0.2-0.4% ointment: Effective but headache common (30-60%).
• Botulinum toxin injection: Off‑label, used in refractory cases.
• Internal sphincterotomy: Rare in children; reserved for severe refractory cases due to risk of incontinence.
🗨️ Examiner Q&A · Anal Fissure · Pathophysiology, Management, Red Flags
❓ Q1 (Examiner): “What is the most likely diagnosis in this child with painful defecation, bright red blood on stool surface, and a sentinel tag?”
✅ Chronic anal fissure secondary to functional constipation. The sentinel tag indicates chronicity. The history of hard stools, pain, withholding behavior, and blood on the surface (not mixed) is classic.
❓ Q2 (Examiner): “Explain the pathophysiology of anal fissure and the vicious cycle of constipation.”
✅ Passage of a hard, large‑diameter stool causes a linear tear in the anoderm (usually posterior midline). The tear exposes the internal anal sphincter, leading to pain and reflex sphincter spasm. Pain causes the child to withhold stool to avoid painful defecation. Stool remains in the rectum longer, becomes harder and larger → further trauma → cycle continues.
❓ Q3 (Examiner): “How would you treat this child (acute management)?”
✅ First-line (acute fissure):
1. Disimpaction if rectal impaction present (PEG 3350 1-1.5 g/kg/day for 3-6 days).
2. Maintenance stool softener: PEG 3350 (0.5-1 g/kg/day) – continue for at least 2 months after regular soft stools.
3. Dietary: increase fluids, fiber (fruits, vegetables, whole grains).
4. Sitz baths: warm water for 10-15 minutes after bowel movements to relax sphincter.
5. Positive reinforcement for toilet sitting.
1. Disimpaction if rectal impaction present (PEG 3350 1-1.5 g/kg/day for 3-6 days).
2. Maintenance stool softener: PEG 3350 (0.5-1 g/kg/day) – continue for at least 2 months after regular soft stools.
3. Dietary: increase fluids, fiber (fruits, vegetables, whole grains).
4. Sitz baths: warm water for 10-15 minutes after bowel movements to relax sphincter.
5. Positive reinforcement for toilet sitting.
❓ Q4 (Examiner): “This fissure has been present for 8 weeks despite stool softeners. What next?”
✅ Chronic fissure treatment:
• Topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%) ointment applied BID to anal canal for 4-8 weeks.
• These relax the internal anal sphincter, reduce spasm, and improve blood flow to the fissure.
• Continue stool softeners and sitz baths.
• If no improvement after 8 weeks, refer to pediatric surgery (botulinum toxin or sphincterotomy – rarely needed).
• Topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%) ointment applied BID to anal canal for 4-8 weeks.
• These relax the internal anal sphincter, reduce spasm, and improve blood flow to the fissure.
• Continue stool softeners and sitz baths.
• If no improvement after 8 weeks, refer to pediatric surgery (botulinum toxin or sphincterotomy – rarely needed).
❓ Q5 (Examiner): “What are the red flags that would make you suspect Crohn disease in a child with anal fissure?”
✅ Red flags for Crohn disease:
• Lateral or multiple fissures (classic fissure is posterior midline).
• Perianal skin tags (edematous, cyanotic).
• Poor healing despite optimal medical therapy.
• Oral ulcers, abdominal pain, chronic diarrhea, weight loss, perianal abscess/fistula.
• Family history of inflammatory bowel disease.
• Extraintestinal manifestations: arthritis, erythema nodosum, uveitis.
• Elevated fecal calprotectin (>200-300 µg/g).
• Lateral or multiple fissures (classic fissure is posterior midline).
• Perianal skin tags (edematous, cyanotic).
• Poor healing despite optimal medical therapy.
• Oral ulcers, abdominal pain, chronic diarrhea, weight loss, perianal abscess/fistula.
• Family history of inflammatory bowel disease.
• Extraintestinal manifestations: arthritis, erythema nodosum, uveitis.
• Elevated fecal calprotectin (>200-300 µg/g).
❓ Q6 (Examiner): “What is the role of anorectal manometry or biopsy in anal fissure?”
✅ Not routinely indicated. Manometry may show high resting anal pressure, but it does not change management. Rectal suction biopsy is only considered if Hirschsprung disease is suspected (rare presentation with fissure). In chronic fissure with red flags, colonoscopy with biopsies is indicated to rule out Crohn.
❓ Q7 (Examiner): “How long should stool softeners be continued after the fissure heals?”
✅ At least 2 months after establishing regular soft stools. Constipation treatment is often required for 6-12 months to prevent relapse. Abrupt discontinuation of PEG may lead to recurrence of hard stools and fissure. Gradual taper over weeks to months.
❓ Q8 (Examiner): “The mother asks: ‘Is surgery necessary for this sentinel tag?’ – Your answer?”
✅ “No, surgery is not needed. The sentinel tag is a benign skin tag that results from chronic inflammation. Once the fissure heals and constipation is treated, the tag may become smaller but usually remains. It does not cause symptoms and does not require excision. Surgery is reserved for refractory fissures that do not heal with medical therapy, which is very rare in children.”
❓ Q9 (Examiner): “What is the most common side effect of topical nitroglycerin and how do you manage it?”
✅ Headache (occurs in 30-60% of patients). Management: use a smaller amount of ointment, apply only to the anal verge, wash hands immediately. If headache persists, switch to nifedipine ointment (fewer headaches, similar efficacy). Also can pre‑treat with acetaminophen 30 minutes before application.
❓ Q10 (Examiner): “A 2‑year‑old has an anterior midline fissure. Does this change your differential?”
✅ Yes. While most fissures are posterior midline, an anterior fissure may be seen in girls and is usually benign. However, lateral fissures or multiple fissures are suspicious for Crohn disease. Anterior fissures without other red flags are still likely functional, but if associated with poor healing or perianal tags, evaluate for Crohn.
📢 Examiner probe (counseling): “The parents are afraid that the sentinel tag might be cancerous. How do you counsel them?” → Explain that the sentinel tag is a benign skin tag caused by chronic inflammation and healing, not a malignancy. It does not require removal unless causing symptoms. Reassure that with proper constipation management, symptoms will resolve.
📘 Nelson's Textbook of Pediatrics – Chapter 392.2: Anal Fissure (Core Summary)
📖 Definition
Linear tear in the anal mucosa, usually posterior midline. Most common cause of painful defecation in infants and toddlers.
Linear tear in the anal mucosa, usually posterior midline. Most common cause of painful defecation in infants and toddlers.
📊 Epidemiology
Common in infants (first year) and children with chronic constipation. Equal gender distribution.
Common in infants (first year) and children with chronic constipation. Equal gender distribution.
🩺 Clinical features
Pain with defecation (crying, screaming), bright red blood on stool surface, withholding behavior. Chronic: sentinel tag.
Pain with defecation (crying, screaming), bright red blood on stool surface, withholding behavior. Chronic: sentinel tag.
🔬 Diagnosis
Clinical: gentle buttock separation reveals linear tear. No tests needed unless atypical.
Clinical: gentle buttock separation reveals linear tear. No tests needed unless atypical.
💊 Management – Acute
Stool softeners (PEG 3350), increased fluids/fiber, sitz baths. Most heal within 1-2 weeks.
Stool softeners (PEG 3350), increased fluids/fiber, sitz baths. Most heal within 1-2 weeks.
💊 Management – Chronic
Topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%) BID for 4-8 weeks.
Topical nifedipine (0.2-0.3%) or nitroglycerin (0.2-0.4%) BID for 4-8 weeks.
🚨 Red flags (Crohn)
Lateral or multiple fissures, perianal skin tags, poor healing, oral ulcers, weight loss, diarrhea.
Lateral or multiple fissures, perianal skin tags, poor healing, oral ulcers, weight loss, diarrhea.
💢 Surgery (rare)
Internal sphincterotomy reserved for refractory cases (risk of incontinence). Botulinum toxin as alternative.
Internal sphincterotomy reserved for refractory cases (risk of incontinence). Botulinum toxin as alternative.
📈 Prognosis
Excellent with medical management. Recurrence prevented by maintaining soft stools.
Excellent with medical management. Recurrence prevented by maintaining soft stools.
📖 Nelson's Textbook Reference (22nd Edition, Section 392.2):
“Anal fissure is characterized by pain with defecation and bright red blood on the stool surface. The condition is almost always associated with constipation. Treatment is directed at producing soft stools with increased fluids, dietary fiber, and stool softeners. Sitz baths and topical anesthetics may provide symptomatic relief. Chronic fissures may benefit from topical nifedipine or nitroglycerin. Surgical sphincterotomy is rarely indicated in children.”
“Anal fissure is characterized by pain with defecation and bright red blood on the stool surface. The condition is almost always associated with constipation. Treatment is directed at producing soft stools with increased fluids, dietary fiber, and stool softeners. Sitz baths and topical anesthetics may provide symptomatic relief. Chronic fissures may benefit from topical nifedipine or nitroglycerin. Surgical sphincterotomy is rarely indicated in children.”
⭐ TOACS TAKE‑HOME POINTS (Anal Fissure – Nelson 392.2):
1. Diagnosis: painful defecation + bright red blood on stool surface + posterior midline tear.
2. Sentinel tag indicates chronic fissure.
3. Primary cause: chronic constipation → hard stool → tear.
4. First-line treatment: PEG 3350, fluids, fiber, sitz baths.
5. Chronic fissure (>6 weeks): add topical nifedipine or nitroglycerin.
6. Lateral or multiple fissures → suspect Crohn disease.
7. Perianal tags, oral ulcers, weight loss, diarrhea → evaluate for IBD.
8. Surgery (sphincterotomy) rarely needed in children.
9. Stool softeners should be continued for at least 2 months after healing.
10. Parental reassurance: excellent prognosis, sentinel tag is benign.
1. Diagnosis: painful defecation + bright red blood on stool surface + posterior midline tear.
2. Sentinel tag indicates chronic fissure.
3. Primary cause: chronic constipation → hard stool → tear.
4. First-line treatment: PEG 3350, fluids, fiber, sitz baths.
5. Chronic fissure (>6 weeks): add topical nifedipine or nitroglycerin.
6. Lateral or multiple fissures → suspect Crohn disease.
7. Perianal tags, oral ulcers, weight loss, diarrhea → evaluate for IBD.
8. Surgery (sphincterotomy) rarely needed in children.
9. Stool softeners should be continued for at least 2 months after healing.
10. Parental reassurance: excellent prognosis, sentinel tag is benign.
🔗 Additional resources:
• Paeds.online – FCPS Paediatrics TOACS station library
• NASPGHAN guidelines for functional constipation and anal fissure
• Paeds.online – FCPS Paediatrics TOACS station library
• NASPGHAN guidelines for functional constipation and anal fissure