Anorectal malformations are usually diagnosed at birth, but some patients have presented to this institution beyond the early newborn period without recognition of their anorectal malformations. To quantify the extent of this problem, we undertook a review of all patients presenting to this hospital with anorectal malformations. We reviewed all new cases of anorectal malformations treated at British Columbia's Children's Hospital during the past 11 years. We looked specifically at the time of diagnosis, patient age, sex and mode of presentation, the type of anorectal malformations, and any associated anomalies. One hundred twenty new cases of anorectal malformations were seen here, of whom, 15 patients (9 girls and 6 boys) presented beyond the early newborn period. Of these, 1 male infant was diagnosed at 2 weeks of age and another girl at 14 years of age. The remaining 13 presented between 3 and 11 months of age because of increasing constipation, usually associated with the introduction of solid foods. All had low anorectal malformations. Nine patients had at least 1 other feature of the VACTERL complex. Most anorectal malformations are identified at birth, but a significant number of the milder lesions may not be recognized until later. Therefore, this condition must be considered in older infants and children presenting with constipation, particularly if they also have cardiac or genitourinary anomalies. constipation, imperforate anus, VACTERL.