Postprandial changes in small bowel water content in healthy subjects and patients with irritable bowel syndrome

Gastroenterology. 2010 Feb;138(2):469-77, 477.e1. doi: 10.1053/j.gastro.2009.10.055. Epub 2009 Nov 10.


Background & aims: Postprandial symptoms are common in patients with irritable bowel syndrome with diarrhea (IBS-D) and could be diet related. We studied postprandial changes in distribution of water in the upper gastrointestinal tract of healthy volunteers (HVs) and patients with IBS-D after contrasting meals.

Methods: In study 1, 11 HVs consumed 350-mL test meals with 5% mannitol (unabsorbable) or 5% glucose (readily absorbed). In study 2, 17 HVs consumed a 331-kcal meal, with or without 15 g bran. In study 3, 26 patients with IBS-D consumed the study 2 diet with bran meal. All subjects underwent serial magnetic resonance imaging analysis.

Results: In study 1, subjects' small bowel water content (SBWC) increased after the mannitol but not glucose meals, reaching 381 mL (interquartile range, 343-491 mL) and 47 mL (18-78 mL), respectively, 40 minutes after eating (P < .001). In study 2, SBWC initially decreased after both meal types and then increased, plateauing at 180-405 minutes and was greater after the bran meal (P = .02). In study 3, fasting and postprandial SBWC was lower in IBS-D than in HVs (P < .05 and P < .0001, respectively). Patients with IBS-D had faster orocecal transit times (135 minutes; 90-180 minutes) compared with HVs (225 minutes; 203-293 minutes; P < .0001) and reduced terminal ileum diameter (P < .003).

Conclusions: Postprandial SBWC initially decreases, because of rapid, nutrient-driven fluid absorption, and then increases after a mixed liquid/solid meal. Patients with IBS-D have reduced fasting and postprandial SBWC with faster transit, possibly indicating increased small intestinal tone.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Cross-Over Studies
  • Dietary Fiber / metabolism
  • Female
  • Gastrointestinal Motility / physiology
  • Glucose / metabolism
  • Humans
  • Intestinal Absorption / physiology*
  • Intestine, Small / metabolism*
  • Irritable Bowel Syndrome / physiopathology*
  • Magnetic Resonance Imaging
  • Male
  • Mannitol / metabolism
  • Middle Aged
  • Postprandial Period / physiology*
  • Water / metabolism*


  • Dietary Fiber
  • Water
  • Mannitol
  • Glucose