While acute necrotizing enterocolitis is a common neonatal condition, the chronicity of the pathologic process is often overlooked. Between 1979 and 1983 at the Foothills Hospital in Calgary, a diagnosis of acute necrotizing enterocolitis was made in 211 infants. Seventeen infants (8%) required urgent surgical treatment in addition to standard medical management. Overall, 206 (98%) infants survived the acute episode. Long-term survival was 92% (194 children). The 12 late deaths were ascribed to chronic cardiovascular, pulmonary and cerebral diseases and "short gut syndrome". Colonic strictures developed in 9% of those treated medically; strictures distal to the mucous fistula developed in 50% of those requiring urgent resection and exteriorization. None of the strictures, which formed between 14 days and 18 months after the diagnosis was made, resolved spontaneously. They tended to be multiple and to involve longer segments in infants who required surgery. Diarrhea prolonged the morbidity in these children. The time course and varied presentation of strictures in this series suggests a rationale for management of infants who survive acute necrotizing enterocolitis.