&NA;Anorectal manometry under anesthesia was performed in 18 children, 15 of whom had long histories of constipation and had been on regular regimens of laxatives and enemas with no success. In these 15 patients, Hirschsprung's disease had not been demonstrated by barium enema. Anesthesia was induced and maintained with ketamine (intravenously or intramuscularly) in 16 patients, while halothane was used in the other two. It was found that anesthesia did not affect the events that are usually documented during anorectal manometry in the awake patient. In patients with a history of constipation, after mamometry, a rectal suction biopsy was taken, followed by a therapeutic anal stretch. Results of biopsies confirmed the manometric findings in all patients. Results of the present study demonstrate that ketamine may be used to anesthetize young patients suffering from chronic constipation for the purpose of performing anorectal manometry and taking a rectal suction biopsy (to exclude Hirschsprung's disease), followed by a therapeutic anal stretch.