A barium enema x-ray is one diagnostic test that may be used to diagnose chronic constipation. It takes a picture of your intestines, colon, and rectum so that a doctor can look for tears and blockages that may be causing your chronic constipation.
The test requires you to clean out your lower intestines the night before the procedure by drinking a substance that helps flush the waste out of your colon and rectum. On the day of the procedure, you will be asked to swallow a white substance called barium. The barium is a dye used to coat the colon and rectum to help them show up on the x-ray. You are then positioned on a table where an x-ray is taken of the lower half of your body. For a few days after the test you may notice your stool is white, caused by the barium exiting your body.