Constipation: definition and classification

Abstract

When a patient complains of constipation it is important to find out exactly what is meant by the term. A detailed history, general physical examination, digital examination of the anus and rectum, sigmoidoscopy and possibly barium enema or other investigations are needed to exclude recognized clinical causes of decreased bowel frequency or difficulty in passing the stools.

Among patients without obvious disease, a frequency of fewer than three bowel actions weekly is found in less than 1% of the population. Some patients complaining of decreased bowel frequency in fact pass a normal number of stools each week.

The intestinal transit rate of patients complaining of consipation may be measured simply using radio-opaque markers. Those patients with a normal transit rate do not need chemical or osmotic laxatives, though a bulk laxative may be helpful. Patients with a slow transit rate appear to need regular laxatives. A few patients are seen who conceal their bowel actions. Some young patients have a normal transit rate round the colon but stools accumulate in a large and insensitive rectum. These patients do not require laxatives so much as training and local treatment to help the rectum to empty.