Hirschsprung's disease (HD), a classic disease of childhood, may rarely escape diagnosis and lead to unique presentations in adults. By definition, the disease involves the rectosigmoid colon and is the result of a birth defect characterised by the absence of nerve cells responsible for the movement of the colon; thereby leading to functional obstruction. We present here a case of an 18-year girl who visited multiple doctors for the complaints of chronic constipation, abdominal distension, and failure to thrive since infancy. Based on a full-thickness rectal biopsy, she was ultimately diagnosed as a case of HD in our Unit. A defunctioning loop ileostomy for colonic decompression, followed by a Swenson Abdominoperineal Pull- Through at a six weeks interval was done, which proved curative.