II. Pathophysiology
- Usually follows Trauma or Diarrheal illness
- Chronic increase in resting anal pressure
- Increased anodermal Blood Flow causes fissures
- Relative ischemia in posteromedial anal region
III. Epidemiology
- Affects young and middle-aged adults
- Men and women are equally affected
IV. Symptoms
- Onset after forced hard Bowel Movement
- Bright red Rectal Bleeding
- Pain during Bowel Movement
- Cut with sharp glass Sensation
- Pain persists for an hour after stooling
V. Signs
- See Anorectal Exam
- Avoid Anoscopy if possible
- Painful and usually not needed
- Use Local Anesthesia if performed
- Crack or crevice in anoderm at anal verge
- Usually in canal midline (anterior 12:00 or posterior 6:00)
- Lateral suggests other diagnosis (see differential diagnosis below)
- Best seen with lateral traction on opposite buttock
- Sentinel pile (distal Skin Tag)
- Tag-like swelling of fissure end
- Results from infection and edema
- Findings suggestive of chronic Anal Fissure (>8 weeks)
- Anal Papillae Hypertrophy
- Sentinel pile or tag (see above)
- Exposed anal sphincter Muscle
VI. Differential Diagnosis
- See Anorectal Pain
- Conditions resulting in lateral Anal Fissure or multiple Anal Fissures
- Inflammatory Bowel Disease (esp. Crohn's Disease)
- HIV Infection
- Tuberculosis
- Syphilis
- Leukemia
- Anorectal cancer
- Sexual Abuse (children)
VII. Management: Medical
- Early Management (especially if <4 weeks)
- Bowel regimen to allow for at least one soft stool daily without straining
- Bulk Dietary Fiber to 30 grams/day
- Increase fluid intake 64 ounces/day
- Topical Anesthetics (e.g. 5% Lidocaine or Xylocaine ointment)
- Short-term use externally only
- Best used prior to having a Bowel Movement
- As an alternative, small amount of shaving cream may be applied to the anus prior to Bowel Movement
- Not evidence-based, but readily available, and unlikely to cause harm
- Fisher and Swaminathan (2023) MacGyver Moves: Anal Care, EM:RAP
- Cold pack applied to anal area
- Warm sitz bath in tub for 20-30 minutes twice daily
- No evidence of benefit, but may be soothing and is without risk
- A plastic bed pan with warm water can be used by patients when not at home (e.g. at work, in bathroom stall)
- Topical Hydrocortisone (e.g. Proctofoam HC)
- Topical Calcium Channel Blocker (see below)
- Rectal Nitroglycerin, typically as Glyceryl Trinitrate ointment (compounded by pharmacist)
- Apply 0.2% twice daily for 6 weeks
- See Rectal Nitroglycerin (Glyceryl Trinitrate, Rectiv)
- Effective, but Headache occurs in 30% of patients (20% stop medication)
- McLeod (2002) J Gastrointest Surg 6(3): 278-80 [PubMed]
- Topical Calcium Channel Blocker
- See below
- Bowel regimen to allow for at least one soft stool daily without straining
- Late Management (esp. >3 months)
- Difficult to treat if persistent beyond 3 months
- Topical Calcium Channel Blocker
- Preparations (compounded by pharmacist)
- Topical Nifedipine 0.3% or 0.5% and Lidocaine 1.5% ointment or
- Topical Diltiazem 2% and Lidocaine 1.5% ointment
- Dosing
- Apply twice daily for 6 weeks
- Efficacy
- More effective than Nitroglycerin Ointment (and fewer adverse effects)
- Resulted in 94.5% rate of healing
- Perrotti (2002) Dis Colon Rectum 45:1468-75 [PubMed]
- Preparations (compounded by pharmacist)
VIII. Management: Invasive Procedures
- Indications
- Failure to improve after above management including two cycles of topical Calcium Channel Blocker (see above)
- Lateral sphincterotomy (preferred)
- Efficacy
- Fissures heal in 96% of cases
- Patients satisfied in 98% of cases
- Complications
- Recurrent Anal Fissures: 8%
- Fecal Incontinence may affect up to 30% of patients
- Severe anal Incontinence reported in 1% (more common in women)
- Fecal Incontinence is less common when surgery is limited to the fissure apex
- Anocutaneous flap may be used in combination in patients at higher risk of Incontinence
- References
- Efficacy
-
Botulinum Toxin Injection
- Unclear long term efficacy
- Dosing
- Initial: Botulinum Toxin 40 units
- Next: Botulinum Toxin 40 units
- Adverse effects
- Short term Fecal Incontinence in 5-7%
- Long term flatus Incontinence is uncommon
- References