AN OVERVIEW OF THE EFFECTS OF DIETARY FIBER ON GASTROINTESTINAL TRANSIT

This article is a review of the effects that ingested dietary fiber ha s on gastrointestinal transit time. The various phases of gastrointest inal motility are considered, and the effect of fiber on these various components is explored. Fiber affects each phase of gastrointestinal motility differently; however, the most dramatic effect on decreased t ransit time and frequency of bowel movements results from the variatio ns it causes in colonic transit time. The mechanisms of defecation in children and the ways in which fiber affects the frequency of bowel mo vements are emphasized. All types of fiber do not affect gastrointesti nal transit in a similar manner, and different preparations of the sam e fiber either may delay or may increase the time of intestinal transi t. In general, fiber is found to increase the frequency of bowel movem ents and may prove to be of considerable benefit in treating constipat ion, a common childhood disorder.