Barium Enema The large intestine can be examined by contrast enema which may be simple contrast when only barium sulphate is use . This is done mainly in bleeding per rectum , colitis , alnd suspected large bowel obstruction Patient preparation Patient preparation is extremely important before this procedure is performed . The colon must be completely empty of all its contents . Different methods are used in different departments to achieve this . The full cooperation of the patient is most essential for this examination . The patient should be instructed • ( 1 ) to keep the anal sphincter tightly contracted over the enema to tube prevent leakage , • ( 2 ) to relax the abdominal muscles , • ( 3 ) to concentrate on deep oral breathing . The patient should undress completely and wear an open backed gown . The be...