A 32-month-old girl had occasional vomiting and abdominal pain of two weeks' duration that became more severe on the day of admission. On physical examination her general condition was satisfactory, but she was febrile (temperature, 39°C). Her abdomen was tender, especially over the right lower quadrant. Abdominal roentgenography showed evenly distributed gas in nondilated intestinal loops and a moderately dilated stomach. Despite a presumptive diagnosis of acute appendicitis, during the next 24 hours all the symptoms and signs gradually subsided and she was discharged.
Ten weeks later the girl was readmitted because of high fever during the preceding week, abdominal pain for four days, and profuse diarrhea (about 15 watery stools) during the preceding 24 hours. On physical examination, she had a low-grade fever (temperature, 37.7°C) but looked generally well. Her blood pressure was 95/60 mm Hg. Her tonsils were slightly enlarged and hyperemic. She had diffuse, mild abdominal tenderness