A 16-year-old adolescent has had lifelong constipation. He

A 16-year-old adolescent has had lifelong constipation. He requires suppositories and, often, enemas to initiate bowel movements. His abdomen is distended. Palpation reveals a tubular mass in the left lower quadrant. Rectal examination reveals no stool in the vault. Barium enema reveals a dilated colon above a normalappearing rectum. Which of the following is the most likely diagnosis? a. Colon carcinoma b. Gardner syndrome c. Peutz-Jeghers syndrome d. Hirschsprung diseasee. Volvulus