Prevalence and outcome of allergic colitis in healthy infants with rectal bleeding: a prospective cohort study.

OBJECTIVES: Allergic colitis is often diagnosed clinically in healthy infants with rectal bleeding and often treated with costly hypoallergenic formula. The true prevalence of allergic colitis is unknown. We tested the hypothesis that allergic colitis is overdiagnosed in healthy infants with rectal bleeding. The authors also determined whether rectal bleeding in infants without allergic colitis would resolve without diet change. METHODS: For the purposes of this study, allergic colitis was defined histologically as colonic mucosa with >or= 6 eosinophils per high power field and/or eosinophils in colonic crypts or muscularis mucosae. We surveyed all 56 Ohio NASPGHAN members to determine standard practice regarding the evaluation of rectal bleeding in infants. In addition, infants