The incidence of Hirschsprung's disease (HD) was determined in children who presented with constipation to a specialist paediatric surgical unit. During a 5-year period, 355 rectal biopsies were performed on 182 neonates, infants and children presenting with chronic constipation or intestinal obstruction: 25 (14%) were diagnosed HD. One hundred and four patients had suction and 78 had full-thickness rectal biopsies. Haematoxylin-eosin (HE) staining and acetylcholinesterase (AChE) histochemistry was used. In 13 cases (8%) of suction and 2 cases (2.5%) of full thickness rectal biopsies, specimens were inadequate to diagnose HD. The mean age of all patients was 2.9 years and that of patients diagnosed with HD was 3.64 months. Nineteen patients with HD were diagnosed in the first month, 5 in 1-12 months and 1 at 4 years of age (Fig. 1). The authors found that along with onset of constipation convincing indications for rectal biopsy to exclude HD were as follows: those infants and children who do not pass meconium within 48 hours, have low intestinal obstruction of unknown cause, severe constipation, chronic abdominal distension and failure to thrive. A diagnostic accuracy of 94% was achieved with AChE histochemistry for suction rectal biopsy. After this review, referring paediatricians were advised that screening of other common organic causes of constipation with the least invasive investigations, including laboratory, dietary and paediatric gastroenterology advice, should be undertaken to avoid unnecessary rectal biopsy to exclude HD and related disorders.