Solitary rectal ulcer syndrome

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Solitary rectal ulcer syndrome (SRUS) is a chronic, benign disorder characterized by the presence of an abnormality of the rectum in persons who have a long history of straining during defecation. It is a misnomer because only a third of patients have a solitary ulcer, and many have no ulcers at all.

Epidemiology

Only 35% of cases have a solitary ulcer of the rectal wall. 22% have multiple ulcers. 43% have no ulcers at all. It typically occurs in young adults, with a slightly increased female predilection.

Clinical presentation

Diagnosis is delayed in many cases because of its rarity, non-specific presentation and multifactorial nature. Major complaints include:

Pathology

Etiology

Two functional disorders of defecation have been recognized:

  • Rectal intussusception
  • Spastic pelvic floor syndrome

    • The rectal wall invaginates into the distal portion of the rectal lumen or the anal canal. Invagination of the rectal wall causes stretching of submucosal vessels, ischemia, and ulceration.

    The rectal abnormality has specific histologic features:

    • replacement of the lamina propria by fibroblasts
    • marked thickening of the muscularis mucosae

    A definitive diagnosis of the syndrome requires a rectal biopsy.

    Radiographic features

    Fluoroscopy
    Barium enema
    • findings on barium enema may be normal or non-specific, consisting of
      • thickened valve(s) of Houston
      • nodularity
      • rectal stricture
      • circular narrowing of distal rectum may be noted
      • ulcer is variably identified
    Defecating proctogram
    • spastic pelvic floor syndrome: inability for the pelvic floor to relax during the straining phase
    • rectal wall infoldIngs slowly leading to an intussusception

    Treatment and prognosis

    • dietary and behavioral modifications are especially effective in patients with mild to moderate symptoms and with an absence of significant mucosal prolapse
      • patient education
      • high fiber diet
      • bulk laxatives
      • avoidance of straining
      • regulation of toilet habits
      • cognitive behavioral therapy (CBT) to ameliorate psychosocial factors
    • for resistant symptoms
      • more organized form of behavioral therapy, e.g. biofeedback therapy may be warranted
    • advanced grade of rectal intussusception, extensive inflammation, established fibrosis and/or irreducible external prolapse:
      • botulinum toxin injection
      • surgery