Diagnosis of Constipation

A diagnosis of constipation involves at least two of the following symptoms for 12 weeks (not necessarily consecutive weeks) during the past 12 months. Symptoms include the following:

  • Fewer than three bowel movements per week
  • Hard stool
  • Straining during bowel movements
  • Sensation of incomplete evacuation or intestinal blockage

Physical examination often includes a digital rectal exam (DRE). In DRE, the physician inserts a lubricated, gloved finger into the patient's rectum to detect tenderness, blockage (e.g., colorectal polyp), or blood.

Diagnostic tests that may be performed include the following:

  • Anorectal function tests—These tests are used to evaluate the function of the anus and rectum.
  • Barium enema—This tests uses x-rays and a contrast solution to view the rectum, colon, and lower portion of the small intestine.
  • Colonoscopy or sigmoidoscopy—These tests involve using a flexible tube with a light and camera attached to view the inside of the colon.
  • Colorectal transit study—This test evaluates how well food moves through the colon. The patient swallows capsules containing markers that are visible on x-ray and a series of x-rays is taken 3–7 days later.
  • Defecography—This test uses x-rays to evaluate how well stool is eliminated through the rectum and anus.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 28 Feb 2008

Last Modified: 08 Sep 2015