CLINICAL History.—A 23-month-old boy was well until three days before admission when he had the onset of intermittent abdominal pains. These episodes would persist for several minutes, during which time he became pale, cried, and would double up with pain. Shortly thereafer, the parents noted the occurrence of a few loose stools daily, none of which contained blood. He vomited once and did not have a bowel movement during the day before admission. He was seen by a physician and referred to the Los Angeles Childrens Hospital because of possible intussusception.
At the time of admission, the child appeared moderately ill, with a temperature of 101.1 F (38.4 C), pulse rate of 110, and respiration rate of 26. The abdomen was distended, with resistance to palpation over both lower quadrants, but no mass was felt. Nothing abnormal was felt on rectal examination. Other abnormalities were not detected in the