Anal fissure

Disease Description (Causes and Symptoms)

• Definition and pathophysiology: A condition in which the anal mucosa (the skin/mucosa around the anus) tears; more than 90% occur posteriorly (on the posterior midline). The main mechanism is reduced blood flow caused by high pressure and spasm of the sphincter within the anal canal (especially the internal sphincter), due to mechanical injury from hard stool, resulting in a wound that does not heal easily.
• Main causes: Constipation (hard stool), excessive pressure/straining during bowel movements, childbirth or trauma, chronic diarrhea, inflammatory bowel disease (e.g., Crohn’s disease), and, rarely, infectious or neoplastic causes.
• Main symptoms: Severe, tearing pain during bowel movements, pain that persists after bowel movements, bright-red rectal bleeding (usually a small amount), itching, or localized inflammation. When the condition becomes chronic, granulation tissue (flesh resembling scar tissue) or findings of a chronic ulcer may be observed at the edges of the wound. If the fissure is in an atypical location (anterior or lateral) or occurs repeatedly, other diseases (e.g., Crohn’s disease, tuberculosis, or tumors) must be differentiated.

Treatment Methods

• Conservative treatment (first-line for most acute cases)
  • Dietary therapy: Increase fiber intake, drink sufficient fluids, and establish regular bowel habits.
  • Use stool softeners (for intermittent constipation) and laxatives (if necessary).
  • Warm sitz baths (several times a day, including after bowel movements) to relieve sphincter spasm.
  • Relieve pain with analgesics (oral or topical).
  • Topical medications: Nitrate-based medications (nitroglycerin ointment) or calcium channel blockers (topical diltiazem/nifedipine ointment) relax the internal sphincter and increase the healing rate. (Nitroglycerin may cause side effects such as headache and hypotension.)
• Medication/injection therapy
  • Botulinum toxin (injection into the internal sphincter): Induces healing through temporary paralysis of the sphincter. May be considered when conservative treatment fails.
• Surgical treatment (for chronic cases or when conservative treatment fails)
  • Lateral internal sphincterotomy: Partially cutting the internal sphincter lowers sphincter pressure and induces healing. It has a high healing rate (successful in most cases), but a small number of patients may face a potential risk of fecal incontinence.
  • Fissurectomy may be performed at the same time if necessary.
• Additional diagnostic and treatment considerations
  • When the fissure is in an atypical location or there are recurrent or atypical findings, rule out inflammatory bowel disease and other lesions through colonoscopy or other examinations.
• Precautions (self-care)
  • Avoid excessive straining and prolonged time on the toilet; avoid anal irritants (cleansers and rough toilet paper); consult a healthcare professional if there is discomfort related to sexual activity.
  • Maintain anal hygiene before and after surgery, and bowel regulation (fiber and stool softeners) is recommended.

Checklist Before an Outpatient Visit (Items to Prepare, Things to Confirm Before the Visit, and Example Questions)

• Items to prepare (bring with you)
  • A list of currently taken medications (including anticoagulants and antiplatelet drugs) and allergy records
  • Records of previous surgeries (especially anal or rectal surgery) and chronic diseases (such as Crohn’s disease)
  • Recent test results (such as colonoscopy and blood tests) and imaging findings (if available)
  • A symptom diary (symptom onset date, pain intensity and frequency, frequency and amount of bleeding, and stool characteristics)
• Information about questions that is helpful to organize in advance for the outpatient visit
  • When the symptoms began and how they have changed (acute versus recurrent/chronic)
  • The nature of the pain during bowel movements (tearing, burning, etc.) and how long it lasts
  • The color of the bleeding (bright red) and its amount (whether it is only on the toilet paper or also on the stool)
  • Bowel habits (number of bowel movements per day, stool consistency, and whether laxatives are used)
  • Whether systemic symptoms such as fever, weight loss, abdominal pain, or joint pain are present
• Things to tell the healthcare professional in advance when visiting the outpatient clinic (examples)
  • “I am taking anticoagulants.” / “I have chronic diarrhea.” / “A previous colonoscopy showed findings suggestive of Crohn’s disease.”

General Example Questions to Ask the Doctor

• What are the expected effects and common side effects of this medication (topical ointment/oral medication)?
• How likely is it that this will heal with conservative treatment, and how long does it usually take?
• If you recommend surgery (lateral internal sphincterotomy), how long would hospitalization and recovery take, and how high is the risk of incontinence?
• What lifestyle changes should I make to prevent similar symptoms?

Examples of Condition-Specific Questions

• My anal fissure is not in the typical location (posterior midline). Should inflammatory bowel disease such as Crohn’s disease be suspected? Is a colonoscopy necessary?
• Among nitroglycerin ointment, topical calcium channel blockers, and botulinum toxin, which conservative treatment is most recommended in my case? (Please compare the side effects and healing rates.)