A Rare Case of Adult-Onset Rectosigmoid Hypoganglionosis.

BACKGROUND Intestinal hypoganglionosis is very rare and accounts for 3% to 5% of all classified congenital intestinal innervation disorders. Isolated hypoganglionosis of the colon is a particularly rare form of the disease, and differential diagnosis includes association with Hirschsprung's disease and chronic intestinal pseudo-obstruction (CIPO) related to visceral myopathies. Most cases are diagnosed at an early age or in childhood with only a few cases reported in adults. CASE REPORT We report a case of isolated hypoganglionosis of the rectum and sigmoid presenting as an emergency with acute intestinal obstruction in a 20-year-old male patient. A history of chronic constipation was reported since childhood, but this condition had never been investigated. A preoperative CT scan showed a megasigmoid and megarectum. A Hartmann's procedure was performed. The patient made a slow recovery and was discharged on the 12th postoperative day in good condition. Histology showed features consistent with isolated hypoganglionosis, and a full thickness rectal biopsies taken 2 months later confirmed the diagnosis. CONCLUSIONS Isolated hypoganglionosis in an adult is very rare, and a high index of suspicion is warranted in young patients with a history of chronic constipation to avoid delayed presentation as an emergency.