The pathophysiology, diagnosis, and treatment of constipation

Abstract

Background: 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.

Methods: Selective review of the literature.

Results: 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.

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

Keywords: constipation; defecation; dietary fiber; laxatives.

Figure 1

The pharmacology of stimulating laxatives. BHPM; bis-(p-hydroxyphenyl)-pyridyl-2-methane

Figure 2

Melanosis coli: epithelial cells migrating toward the submucosa in the process of apoptosis obtain a black color from anthraquinone and are then phagocytosed. The macrophages take on the black pigment and then migrate away by way of the lymphatic vessels.

Figure 3

Recommended diagnostic and therapeutic algorithm for constipation