ABSTRACT
Diet, in particular dietary fibre, could play a significant role in the absorption of drugs from the colon. Individuals ingesting a vegetarian diet or taking stool bulking agents may possibly show a difference in colonic drug absorption when compared with individuals ingesting a relatively low fibre diet. However, increased dietary fibre leads to decreased gastrointestinal transit times, which may offset any absorptive benefit gained by increasing the mucosal surface area in the colon81. Since fibre alters the transit through the colon it would be expected to have the greatest influence on the absorption of drugs from sustained release preparations. In young vegetarians the mouth to anus transit of a single unit can be less than 6 hours, indeed, for one “normal” subject, the total transit time was 2 hours (Washington et al, unpublished observation).
