A 23-MONTH-OLD seen in the pediatrie emergency department with a chief complaint of acute abdominal pain. The child was reported to have been in excellent health until approximately 1 hour prior to examination, when an acute onset of irritability was noted. He was described as constantly crying since the beginning of the onset of this irritability, and was also noted to be "holding his stomach" in pain. There was no history of trauma, fever, vomiting, diarrhea, constipation, recent travel, or similar episodes. His medical history was significant for bilateral inguinal hernia repair at younger than 1 year, but no other abdominal surgery was noted.
On initial physical examination he was alert, active, afebrile, extremely irritable, and only minimally consolable by his parents. The only remarkable physical finding was found on examination of the abdomen, which was noted to be soft, with hypoactive bowel sounds and an umbilical protuberance measuring 3