The child with a typical history of chronic constipation, and with physical signs of a distended abdomen and an empty rectal ampulla, who is found to have a widely dilated colon with a narrow distal segment by the radiologist, presents no diagnostic problem. However, the diagnosis of Hirschsprung's disease may be very difficult to establish if part of the classical diagnostic criteria are absent or inconclusive. In such cases, the authors have found rectal biopsy to be a useful diagnostic procedure. They cite as indications for biopsy: (1) suspected Hirschsprung's disease in the newborn infant, because the colon does not become dilated and hypertrophied until the intestinal tract has been functioning for several months; (2) symptoms of upper large bowel obstruction developing soon after birth, because barium enema studies of infants whose entire colons are aganglionic reveal no obstruction of the lumen of the large intestine; (3) radiologic evidence of dilatation of the entire distal segment of the colon, because, in patients with a short aganglionic lesion, the obstruction may be so low that the radiologist is unable to demonstrate a narrow segment extending through the rectosigmoid, and (4) atypical symptoms of megacolon, including diarrhea, episodes of intestinal obstruction, or other symptoms of colonic dysfunction.
This procedure has been performed by Swenson and his colleagues on 40 patients. Biopsy specimens obtained from 19 patients, subsequently proved to have Hirschsprung's disease by study of the resected rectum and sigmoid, contained no ganglionic cells. In the other 21 patients, biopsy was performed because Hirschsprung's disease was suspected. Ganglionic cells were present in all of these specimens, and the success of subsequent conservative management of these patients confirmed the diagnosis of chronic constipation. Control material was obtained from 10 cadavers with normal colons, and ganglionic cells were found in all of these specimens.
The authors emphasize that this technique is only as good as the specimen obtained. An adequate biopsy of rectal wall must be removed. Multiple histologic sections must be carefully examined before the diagnosis of Hirschsprung's disease is confirmed.