Alerts and Notices
SynopsisAn anal stricture is a narrowing of the anal canal, which can either be congenital or acquired, typically due to chronic inflammation and subsequent scar formation. There are a variety of etiologies that can lead to acquired anal stricture formation: hemorrhoidectomy (postoperative complication), laxative abuse, radiation therapy, tuberculosis, and inflammatory bowel disease (fibrosis leads to stricture), eg, Crohn disease.
Patients with anal strictures will present with constipation and pain with defecation. They may also have abdominal distention, rectal bleeding, watery rectal discharge from the passage of loose contents around a fecal impaction, and tenesmus.
Treatment of anal stricture is ultimately surgical for complete resolution, except in instances where the stricture is due to inflammation (eg, inflammatory bowel disease) without irreversible fibrosis. In these cases, treatment of the underlying cause may be beneficial. However, since the risks of anoplasty with partial sphincterotomy are considerable, often more supportive measures such as stool softeners, a high-fiber diet, or anal dilatation is attempted as first-line therapy.
K62.4 – Stenosis of anus and rectum
55960007 – Stricture of anal canal
Differential Diagnosis & PitfallsThe differential below mostly includes the etiologies of anal strictures. Rectal cancer or rectal abscesses can presumably be misidentified as anal strictures on imaging, although this is unlikely.
- Hirschsprung disease – congenital; suspect with no passage of meconium within 48 hours of life.
- Meconium ileus – highest incidence in cystic fibrosis.
- Small left colon syndrome
- Inflammatory bowel disease (eg, Crohn disease, ulcerative colitis)
- Radiation therapy (complication)
- Laxative abuse
- Infectious – tuberculosis; complication of anal wart treatment