What are the recommended first-line treatments for an anal fissure in adults?

Initial first-line treatments for anal fissures in adults focus on conservative measures to promote healing and manage symptoms ¹.

• Lifestyle and Bowel Management:
  • Ensure stools are soft and easy to pass through adequate dietary fibre intake (introduced gradually) and sufficient fluid intake ¹.
  • Advise on correct anal hygiene, keeping the area clean and dry ¹.
  • Discourage 'stool withholding' and undue straining during bowel movements ¹.
• Pain Management:
  • Offer simple analgesia such as paracetamol or ibuprofen for prolonged burning pain after defecation, avoiding opioid analgesics due to constipation risk ¹.
  • Advise sitting in a shallow, warm bath several times a day, particularly after a bowel movement, to help relieve pain ¹.
• Topical Medications:
  • For adults experiencing extreme pain on defecation, consider a short course (a few days) of a topical anaesthetic (e.g., lidocaine 5% ointment) for use before passing a stool ¹. This should not be used for longer than a few days due to hypersensitivity risk ¹.
  • If symptoms have been present for 1 week or more without improvement, in addition to lifestyle measures, consider prescribing rectal glyceryl trinitrate (GTN) 0.4% ointment (provided there are no contraindications) to aid healing ¹. Advise application twice a day for 6–8 weeks to allow re-epithelization and reduce the risk of relapse ¹. Patients should be aware that headache is a common side effect ¹. GTN works by relaxing the internal anal sphincter, which improves blood flow and aids healing ¹.