Anal fissure

Background

• Superficial linear tear of anal canal from at/below dentate line to anal verge
  • May be due to passage of hard stool, frequent diarrhea, or abuse
• Most common cause of painful rectal bleeding
• In >90% of cases anal fissures occur in the midline posteriorly
  • Non-healing fissure or one not located in midline suggests alternative diagnosis (e.g. Crohn's, malignancy)

Clinical Findings

• Acute sharp, cutting pain most severe during and immediately after bowel movement
  • Subsides between bowel movements (distinguishes fissure from other anorectal disease)
• Bright red rectal bleeding, small in quantity (usually noticed only on toilet paper)
• Lateral to anus often indicates associated systemic illness such as Crohn's, HIV, leukemia, TB, syphilis

Evaluation

• Having patient bear down may make fissure more noticable
• Sentinel pile, located at distal end of fissure, along with deep ulcer suggests chronicity
  • Often misdiagnosed as an external hemorrhoid

Differential Diagnosis

Anorectal Disorders

• Anal fissure
• Anal fistula
• Anal malignancy
• Anal tags
• Anorectal abscess
• Coccydynia
• Colorectal malignancy
• Condyloma acuminata
• Constipation
• Crohn's disease
• Cryptitis
• GC/Chlamydia
• Fecal impaction
• Hemorrhoids
  • Internal hemorrhoid
  • External hemorrhoid
• Levator ani syndrome
• Pedunculated polyp
• Pilonidal cyst
• Proctalgia fugax
• Proctitis
• Pruritus ani
  • Enterobius (pinworms)
• Rectal foreign body
• Rectal prolapse
• Syphilitic fissure

Non-GI Look-a-Likes

• Prostatitis

Undifferentiated lower gastrointestinal bleeding

• Upper GI Bleeding
• Diverticular disease
  • Diverticulosis
  • Diverticulitis
• Vascular ectasia / angiodysplasia
• Inflammatory bowel disease
• Infectious colitis
• Mesenteric Ischemia / ischemic colitis
• Meckel's diverticulum
• Colorectal cancer / polyps
• Hemorrhoids
  • Internal hemorrhoid
  • External hemorrhoid
• Aortoenteric fistula
  • Nearly 100% mortality if untreated
  • Consider in patients with gastrointestinal bleeding and known abdominal aortic aneurysms or aortic grafts
• Rectal foreign body
• Rectal ulcer (HIV, Syphilis, STI)
• Anal fissure

Management

• Warm sitz baths 15 min TID-QID and after each bowel movement
  • Provides symptomatic relief by improving anal blood flow and relieves anal sphincter spasm
• Topicals
  • Pain control with lidocaine
  • Vasodilators such as nitroglycerin or nifedipine ointment
  • Hydrocortisone
• High-fiber diet
  • Prevents stricture formation by providing a bulky stool
• Meticulous anal hygiene is imperative; after defecation anus must be cleaned thoroughly
• Surgical referral indicated if healing does not occur in a reasonable amount of time

Complications

• Anorectal abscess

Disposition

• Most patients can be managed medically and discharged with outpatient follow-up

See Also

• Anorectal Disorders

External Links

• Merk Manual - Anal Fissure
• EM Ottawa - Hemorrhoids and Anal Fissures in the ED