It also helps the radiologist see the size and shape of the colon and rectum. You may be uncomfortable during the lower GI series. The barium will cause fullness and pressure in your abdomen and will make you feel the urge to have a bowel movement. However, that rarely happens because the tube the physician uses to inject the barium has a balloon on the end of it that prevents the liquid from coming back out. You may be asked to change positions while x-rays are taken.
Different positions give different views of the intestines.
After the radiologist is finished taking x-rays, you will be able to go to the bathroom. The radiologist may also take an x-ray of the empty colon afterwards. A lower GI series takes about 1 to 2 hours. The barium may cause constipation and make your stool turn gray or white for a few days after the procedure. Your colon must be empty for the procedure to be accurate.