π©Ί Symptoms and Signs
- β‘ Severe, sharp anal pain, especially during or immediately after defecation (patients may avoid opening bowels due to fear of pain).
- π©Έ Bright red blood on toilet paper or streaked on stool (typically small amounts).
- π The fissure may be visible on inspection when the buttocks are parted β most commonly in the posterior midline (90%).
- π₯ Acute sphincter spasm, often making digital rectal examination (PR) intolerable.
- π·οΈ Sentinel pile (skin tag) at the anal verge may develop in chronic cases, external to the fissure.
- π Chronic fissures may also show indurated edges and exposure of the internal sphincter fibres.
π Differential Diagnosis
- πΏ Crohn's disease (classically multiple or off-midline fissures).
- β οΈ Trauma (consider possibility of non-accidental injury in children).
- ποΈ Anal carcinoma.
- π¦ Infections: Herpes simplex, Tuberculosis (TB), Syphilis.
- π§΄ Dermatological causes: Psoriasis, lichen sclerosus.
π§ Conservative Management
- π Topical local anaesthetic gel or suppository β best applied ~30 minutes before defecation to ease pain.
- π₯¦ Address constipation: High-fibre diet, adequate hydration, stool softeners (e.g., lactulose, macrogols).
- π Topical GTN (0.2%) ointment twice daily for 6 weeks β relaxes internal sphincter, promotes healing. β οΈ Side effect: headache due to systemic absorption.
- π§΄ Diltiazem (2% cream) is an alternative to GTN, often better tolerated in the UK.
- π Warm sitz baths may help relax sphincter spasm and provide symptomatic relief.
πͺ Surgical / Procedural Management
- β
90% of acute fissures heal with conservative treatment.
- π Botulinum toxin injection into internal anal sphincter can be considered before surgery β reduces spasm, heals ~60β70% of chronic fissures.
- βοΈ Lateral internal sphincterotomy: Standard operation for chronic/refractory fissures β reduces sphincter spasm and allows healing.
- π§Ύ Histology: Tissue excised from recurrent or atypical fissures should be sent for analysis to exclude malignancy or Crohnβs disease.
- π₯ Post-op care: Continue stool softeners, high-fibre diet, and analgesia to prevent recurrence.
- β οΈ Risk of faecal incontinence (especially minor soiling) post-sphincterotomy, though rare in experienced hands.
π‘ Clinical Pearl: In UK practice, fissures off the midline, multiple fissures, or those not healing with standard therapy should raise suspicion for underlying pathology (Crohnβs, TB, HIV, carcinoma). Always think βred flagβ if atypical.