Sir .—We read with interest the article by Berezin et al 1 in the March 1989 issue of AJDC wherein they reported their experience with cow's milk or soy protein—induced colitis in 22 infants. In all 19 of 22 patients who received the protein hydrolysate formula Nutramigen (Bristol-Meyers Inc, USPNG, Evansville, Ind), rectal bleeding ceased. We describe an infant who developed symptoms of allergic colitis while receiving Nutramigen and on repeated challenge with Nutramigen but not with other hypoallergenic feeding. Patient Report .—A 2-month-old white male with bloody diarrhea for 7 days was referred to the pediatric gastroenterology outpatient service of the Schneider Children's Hospital of the Long Island Jewish Medical Center, New Hyde Park, NY, for evaluation in April 1989. He was born without complications, the 3050-g fullterm product of a normal spontaneous vaginal delivery. Initially, the infant was placed on a cow's milk formula but was changed to