A 5HT3 antagonist corrects the postprandial colonic hypertonic response in carcinoid diarrhea

Gastroenterology. 1994 May;106(5):1184-9. doi: 10.1016/0016-5085(94)90008-6.


Background/aims: Carcinoid patients show a hypertonic colonic motor response postprandially. Ondansetron reduces postprandial colonic tone in health. It was hypothesized that ondansetron, a selective 5HT3 antagonist, corrects the colonic motor response to eating in carcinoid diarrhea.

Methods: The effects of ondansetron and placebo on fasting and postprandial colonic tone and motility in 10 patients with carcinoid diarrhea were compared using a manometry-barostat assembly positioned in the upper descending colon.

Results: Fasting colonic tone and motility indices were similar in the placebo and ondansetron groups; ondansetron did not affect fasting motility. The placebo group showed a significant reduction in barostat balloon volume (signifying increased tone) from 207 +/- 29 mL (mean +/- SEM) during fasting to 106 +/- 14 mL postprandially (P = 0.01). With ondansetron, a tonic colonic response was induced postprandially (198 +/- 37 mL to 151 +/- 30 mL; P = 0.053). However, the increment in tone in the ondansetron group (23% +/- 7%) was significantly lower than in the placebo group (48% +/- 5%; P = 0.02) and was similar to that observed in untreated healthy subjects (24% +/- 3%). Postprandial manometric pressure activity increased significantly in the placebo group (P = 0.01); in the ondansetron group there was a trend (P = 0.09) to increased phasic activity.

Conclusions: Ondastetron reduces the postprandial colonic hypertonic response in carcinoid diarrhea to levels previously reported in health; further clinical studies of this class of antagonists in carcinoid diarrhea appear warranted.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Colon / physiopathology*
  • Diarrhea / drug therapy*
  • Diarrhea / physiopathology*
  • Double-Blind Method
  • Eating / physiology*
  • Fasting / physiology
  • Female
  • Gastrointestinal Motility / drug effects
  • Gastrointestinal Motility / physiology
  • Humans
  • Male
  • Manometry
  • Middle Aged
  • Ondansetron / therapeutic use*
  • Serotonin Antagonists / therapeutic use*


  • Serotonin Antagonists
  • Ondansetron