Preoperative and postoperative serum samples of 35 patients with different congenital gastrointestinal anomalies were analyzed for the markers CEA, CA 125 and 19-9 by immunoradiometric assay during a period of three years. The majority of the anomalies were aganglionic megacolon and hypertrophic pyloric stenosis. CA 125 and CA 19-9 were likely to indicate logistic model probabilities for babies with anomalies, while CEA was not (F=35.78, p