Efficacy of open-label bismuth subsalicylate for the treatment of microscopic colitis

Gastroenterology. 1998 Jan;114(1):29-36. doi: 10.1016/s0016-5085(98)70629-8.


Background & aims: The pathogenesis of the microscopic colitis syndrome is unknown but may involve bacteria, an intestinal luminal antigen, and/or autoimmunity. It was hypothesized that bismuth subsalicylate would resolve both diarrhea and colonic inflammation in microscopic colitis because it possesses antidiarrheal, antibacterial, and anti-inflammatory properties.

Methods: Thirteen patients with microscopic colitis (7 with subepithelial collagen deposition and 6 without) were treated with eight chewable 262-mg bismuth subsalicylate tablets per day for 8 weeks. Patients recorded the frequency of bowel movements daily. Forty-eight-hour stool collections and flexible sigmoidoscopy with 24 biopsies were performed before and after treatment in each patient.

Results: Twelve patients completed the trial. Eleven patients had a resolution of diarrhea and a reduction in fecal weight. The average time to respond was 2 weeks. In 9 patients, colitis resolved. When present before treatment, subepithelial collagen thickening disappeared. Those completing the trial experienced no side effects. Posttreatment follow-up for 7-28 months shows that 9 patients remain well having undergone no further treatment, 2 are well but required retreatment, and 1 has continued diarrhea.

Conclusions: Bismuth subsalicylate treatment for 8 weeks is safe and well tolerated. This regimen appears to be efficacious for the treatment of microscopic colitis and is worthy of further study in a controlled trial.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Bismuth / administration & dosage*
  • Bismuth / adverse effects
  • Colitis / drug therapy*
  • Colitis / pathology
  • Colitis / physiopathology
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Organometallic Compounds / administration & dosage*
  • Organometallic Compounds / adverse effects
  • Salicylates / administration & dosage*
  • Salicylates / adverse effects
  • Treatment Outcome


  • Organometallic Compounds
  • Salicylates
  • bismuth subsalicylate
  • Bismuth