Clinical History.—This 7-week-old boy was seen with a history of "colic," starting at 2 weeks of age. He weighed 3,698 gm (8 lb 6 oz) at birth and the pregnancy was uneventful. The mother stated that he had fed eagerly and that his stomach rumbled. He would cry, pull up his legs and wriggle frequently. Sleep periods were usually short, seldom lasting more than 45 minutes. There had been no improvement with antispasmodics or change to a soybean milk formula. An older brother had had a history of severe colic treated as a milk allergy.
Physical Examination.—His weight was 5,613 gm (12 lb 6 oz). He seemed happy and alert. There were no unusual physical findings. The hemoglobin level was 8.1 gm/100 ml, red blood cell count was 3,000,000/cu mm and hematocrit value was 27%. The white blood cell count and differential cell count were normal. The urine had a specific