Anal Fissure

Pathophysiology

Usually follows Trauma or Diarrheal illness
Chronic increase in resting anal pressure
1. Increased anodermal Blood Flow causes fissures
Relative ischemia in posteromedial anal region

Epidemiology

Affects young and middle-aged adults
Men and women are equally affected

Symptoms

Onset after forced hard Bowel Movement
Bright red Rectal Bleeding
Pain during Bowel Movement
1. Cut with sharp glass Sensation
2. Pain persists for an hour after stooling

Signs

See Anorectal Exam
Avoid Anoscopy if possible
1. Painful and usually not needed
2. Use Local Anesthesia if performed
Crack or crevice in anoderm at anal verge
1. Usually in canal midline (anterior 12:00 or posterior 6:00)
2. Lateral suggests other diagnosis (see differential diagnosis below)
3. Best seen with lateral traction on opposite buttock
Sentinel pile (distal Skin Tag)
1. Tag-like swelling of fissure end
2. Results from infection and edema
Findings suggestive of chronic Anal Fissure (>8 weeks)
1. Anal Papillae Hypertrophy
2. Sentinel pile or tag (see above)
3. Exposed anal sphincter Muscle

Differential Diagnosis

See Anorectal Pain
Conditions resulting in lateral Anal Fissure or multiple Anal Fissures
1. Inflammatory Bowel Disease (esp. Crohn's Disease)
2. HIV Infection
3. Tuberculosis
4. Syphilis
5. Leukemia
6. Anorectal cancer
7. Sexual Abuse (children)

Management
Medical

Early Management (especially if <4 weeks)
1. Bowel regimen to allow for at least one soft stool daily without straining
  1. Bulk Dietary Fiber to 30 grams/day
  2. Increase fluid intake 64 ounces/day
2. Topical Anesthetics (e.g. 5% Lidocaine or Xylocaine ointment)
  1. Short-term use externally only
  2. Best used prior to having a Bowel Movement
  3. As an alternative, small amount of shaving cream may be applied to the anus prior to Bowel Movement
    1. Not evidence-based, but readily available, and unlikely to cause harm
    2. Fisher and Swaminathan (2023) MacGyver Moves: Anal Care, EM:RAP
3. Cold pack applied to anal area
4. Warm sitz bath in tub for 20-30 minutes twice daily
  1. No evidence of benefit, but may be soothing and is without risk
  2. A plastic bed pan with warm water can be used by patients when not at home (e.g. at work, in bathroom stall)
5. Topical Hydrocortisone (e.g. Proctofoam HC)
6. Topical Calcium Channel Blocker (see below)
7. Rectal Nitroglycerin, typically as Glyceryl Trinitrate ointment (compounded by pharmacist)
  1. Apply 0.2% twice daily for 6 weeks
  2. See Rectal Nitroglycerin (Glyceryl Trinitrate, Rectiv)
  3. Effective, but Headache occurs in 30% of patients (20% stop medication)
  4. McLeod (2002) J Gastrointest Surg 6(3): 278-80 [PubMed]
8. Topical Calcium Channel Blocker
  1. See below
Late Management (esp. >3 months)
1. Difficult to treat if persistent beyond 3 months
2. Topical Calcium Channel Blocker
  1. Preparations (compounded by pharmacist)
    1. Topical Nifedipine 0.3% or 0.5% and Lidocaine 1.5% ointment or
    2. Topical Diltiazem 2% and Lidocaine 1.5% ointment
  2. Dosing
    1. Apply twice daily for 6 weeks
  3. Efficacy
    1. More effective than Nitroglycerin Ointment (and fewer adverse effects)
    2. Resulted in 94.5% rate of healing
    3. Perrotti (2002) Dis Colon Rectum 45:1468-75 [PubMed]

Management
Invasive Procedures

Indications
1. Failure to improve after above management including two cycles of topical Calcium Channel Blocker (see above)
Lateral sphincterotomy (preferred)
1. Efficacy
  1. Fissures heal in 96% of cases
  2. Patients satisfied in 98% of cases
2. Complications
  1. Recurrent Anal Fissures: 8%
  2. Fecal Incontinence may affect up to 30% of patients
    1. Severe anal Incontinence reported in 1% (more common in women)
    2. Fecal Incontinence is less common when surgery is limited to the fissure apex
    3. Anocutaneous flap may be used in combination in patients at higher risk of Incontinence
3. References
  1. Nyam (1999) Dis Colon Rectum 42:1306 [PubMed]
Botulinum Toxin Injection
1. Unclear long term efficacy
2. Dosing
  1. Initial: Botulinum Toxin 40 units
  2. Next: Botulinum Toxin 40 units
3. Adverse effects
  1. Short term Fecal Incontinence in 5-7%
  2. Long term flatus Incontinence is uncommon
4. References
  1. Arroyo (2005) Am J Surg 189:429-34 [PubMed]
  2. Brisinda (2007) Br J Surg 94(2): 162-7 [PubMed]

References