Megacolon and stercoral proctitis after frequent fecal impactions: report of an unusual case and review of the literature.

Persistent megacolon that results from frequent episodes of fecal impaction without adequate treatment is a rare and seldom reported condition in the elderly. This report discusses a 72-year-old white woman presenting with a large abdominal mass, who had at least 4 episodes of radiographically demonstrated fecal impaction over the previous year without adequate treatment. The patient required hospitalization for a bleeding rectal ulcer during the second episode of fecal impaction. Computed tomography (CT) scans on this admission revealed a dilated colon up to 16 x 14 cm in maximal dimensions extending over 30 cm, filled with massive fecal material. Several follow-up abdominal radiographs revealed a persistent megacolon after 10 months despite the absence of significant fecal material in the rectosigmoid colon. While multiple contributing factors were likely involved in her frequent fecal impactions, the clinical course of this case suggests that frequent fecal impactions without adequate treatment can lead to megacolon in high-risk patients. Clinicians should aggressively treat fecal impaction and monitor the adequacy of treatment with abdominal radiography in order to avoid significant complications. Complications and management of fecal impaction and the pathophysiology of megacolon in the literature are reviewed and discussed.