How effective is nonlaxative treatment of constipation?

In almost any textbook of medicine so-called simple measures are proposed for treating constipation, such as increasing physical activity, drinking more fluid, triggering the gastrocolonic response by, e.g., drinking a glass of water or a cup of coffee, and bowel training. All of these have not been formally evaluated in constipated patients. Biofeedback training is useful for paradoxical puborectal contraction ('anismus'). Dietary fibre, e.g. in the form of wheat bran, increases stool weight and decreases colonic transit time. So every patient should have an empiric treatment with an adequate amount of fibre. Some patients, especially those with slow transit constipation and those with stasis in the right hemicolon, are not likely to respond to a therapy with bran, however.