Diet and transit through the gut

For most adults it takes between 1 and 3 days for material to pass through the gut. When transit is carefully measured considerable variation from day to day, and week to week, is seen. Several factors can be shown to affect transit, including bowel habit, stress, exercise, colonic anatomy and diet, of which dietary fibre is the most important. Fibre, particularly from wheat, has been shown to shorten transit time in many studies. Different types of fibre affect transit in different ways; but, in general, transit varies in relation to changes in faecal weight. The importance of transit has yet to be clarified, but certain metabolic events in the large bowel can be related to it.