Fissure in Ano
🩺 Symptoms and Signs
- ⚡ Severe, sharp anal pain, especially during or immediately after defecation (patients may avoid opening bowels due to fear of pain).
- 🩸 Bright red blood on toilet paper or streaked on stool (typically small amounts).
- 👀 The fissure may be visible on inspection when the buttocks are parted — most commonly in the posterior midline (90%).
- 💥 Acute sphincter spasm, often making digital rectal examination (PR) intolerable.
- 🏷️ Sentinel pile (skin tag) at the anal verge may develop in chronic cases, external to the fissure.
- 🕒 Chronic fissures may also show indurated edges and exposure of the internal sphincter fibres.
🔍 Differential Diagnosis
- 🌿 Crohn's disease (classically multiple or off-midline fissures).
- ⚠️ Trauma (consider possibility of non-accidental injury in children).
- 🎗️ Anal carcinoma.
- 🦠 Infections: Herpes simplex, Tuberculosis (TB), Syphilis.
- 🧴 Dermatological causes: Psoriasis, lichen sclerosus.
🧘 Conservative Management
- 💊 Topical local anaesthetic gel or suppository — best applied ~30 minutes before defecation to ease pain.
- 🥦 Address constipation: High-fibre diet, adequate hydration, stool softeners (e.g., lactulose, macrogols).
- 💊 Topical GTN (0.2%) ointment twice daily for 6 weeks — relaxes internal sphincter, promotes healing. ⚠️ Side effect: headache due to systemic absorption.
- 🧴 Diltiazem (2% cream) is an alternative to GTN, often better tolerated in the UK.
- 🛀 Warm sitz baths may help relax sphincter spasm and provide symptomatic relief.
🔪 Surgical / Procedural Management
- ✅ 90% of acute fissures heal with conservative treatment.
- 💉 Botulinum toxin injection into internal anal sphincter can be considered before surgery — reduces spasm, heals ~60–70% of chronic fissures.
- ✂️ Lateral internal sphincterotomy: Standard operation for chronic/refractory fissures — reduces sphincter spasm and allows healing.
- 🧾 Histology: Tissue excised from recurrent or atypical fissures should be sent for analysis to exclude malignancy or Crohn’s disease.
- 🥗 Post-op care: Continue stool softeners, high-fibre diet, and analgesia to prevent recurrence.
- ⚠️ Risk of faecal incontinence (especially minor soiling) post-sphincterotomy, though rare in experienced hands.
💡 Clinical Pearl: In UK practice, fissures off the midline, multiple fissures, or those not healing with standard therapy should raise suspicion for underlying pathology (Crohn’s, TB, HIV, carcinoma). Always think “red flag” if atypical.
