An Obscure Colon Dilatation and its Underlying Cause: Case Report and Literature Review

Introduction: Congenital as well as acquired diseases may be responsible for the development of a megacolon. In adult patients, Clostridium difficile associated infection as well as late-onset of Morbus Hirschsprung disease are known to cause a megacolon. In addition, malignant as well as benign colorectal strictures may lead to intestinal dilatation. In case of an idiopathic megacolon, the underlying cause remains unclear. Case Presentation: We describe the case of a 44-year-old male patient suffering from a long history of chronic constipation. He presented himself with an obscurely dilated large intestine with bowel loops up to 17 centimeters in diameter. Radiological as well as endoscopic examination gave evidence of a spastic process in the sigmoid colon. The patient was treated with a subtotal colectomy and the intraoperative findings revealed a stenotic stricture in the sigmoid colon. Since the histological examination did not find a conclusive reason for the functional stenosis, an immunohistochemical staining was advised. This showed a decrease in interstitial cells of Cajal (ICC) in the stenotic part of the sigmoid colon. Discussion: This case report describes a patient with an idiopathic megacolon, where the underlying cause remained unclear until an immunohistochemical staining of the stenotic colon showed a substantial decrease of ICCs. Various pathologies leading to a megacolon are reviewed and discussed.