The pathophysiology, diagnosis, and treatment of constipation

Constipation is a common condition about which there are many widespread notions that have no basis in fact. The purpose of this article is to summarize current scientific knowledge on the subject.

Selective review of the literature.

Diagnostic evaluation usually fails to reveal the cause of constipation. It is due to medications in some patients, while endocrine disorders are the cause in only a small minority. Abnormal defecation may be due to dysfunction of the pelvic floor. Most patients complain of abdominal fullness and of needing to strain to pass stool; low stool frequency is a rare symptom. The symptoms alone determine the indication for treatment. Constipation usually poses no threat to health. Some patients are helped by a diet rich in fiber, others by laxatives. A number of laxatives with different modes of action are available; all are safe and generally well tolerated. In some patients, dysfunctional defecation may be an indication for proctological surgery.

The Rome criteria are useful for establishing a specific diagnosis of constipation. Most patients can be helped with laxatives and patient education.