Enema is the procedure of injecting fluids through the rectum into the lower bowel in order to cleanse the lower intestines or to relieve constipation. Generally, water is used to irrigate in a retrograde way to empty the intestines of the feces. Sometimes, baking soda or sodium phosphate is also mixed with water. In case of a special diagnostic procedure that is used to investigate the lower intestinal tract, the colon, and the rectal areas, a procedure called barium enema (See: Barium) is performed. People with symptoms of bleeding in the rectum, abdominal pain, blood in stools, ulcerative colitis, Crohn’s disease, and colorectal cancer are advised to undergo this diagnostic test. To prepare for this test, the patient has to empty the bowels with a laxative the previous night and should only consume fluids on the day of the test. The test itself is performed at a hospital. An enema tube is inserted in the rectum and the tube is in turn connected to a container with barium sulfate. The barium sulfate enters the rectum and the colon and the imaging is done. After the test, the patient is allowed to relieve the barium sulfate through bowel movements. The patient is advised to drink a lot of fluids to flush out the barium sulfate out of the system. Side effects of this test include constipation, and stomach cramps.