Atypical presentation of acute idiopathic megacolon in a 14-year-old patient

In clinical practice the term “megacolon” is used to indicate a marked dilatation of the cecum and the sigmoid colon (>12 and 6.5 cm, respectively) (1). From a clinical standpoint, a megacolon can be classified as chronic or acute depending on its clinical presentation. Chronic megacolon typically refers to a congenital disorder in which the enteric nervous system (ENS) supplying the colon does not develop properly, thereby leaving the distal segments of the viscus without myenteric and submucosal ganglia (i.e. Hirschsprung’s disease) (2). Other cases of non-aganglionic chronic megacolon can be secondary to variety of conditions such as Chagas’ disease and neurodegenerative diseases (e.g. Parkinson’s and Alzheimer’s diseases), leading to or associated with ENS abnormalities (3). The acute form of megacolon, also referred to as Ogilvie’s syndrome, is characterized by a predominant involvement of the cecum and right colon usually affecting elderly patients undergoing surgery (e.g. orthopedic procedures) or taking medications altering gut motility (e.g. opioids or antidepressants) (4). Some forms of acute megacolon, however, can be idiopathic in origin since no underlying etiology can be identified. Patients with acute idiopathic megacolon usually have a longstanding history of constipation, often accompanied by laxative abuse, and their clinical presentation is characterized by abdominal distension and severe pain with radiological evidence of stool impacted in the colon and rectum (1, 4). The case herein reported represents an unusual form of acute idiopathic megacolon characterized by massive descending and sigmoid colon distension complicated with a volvulus in a 14-year-old boy with no Hirschsprung’s disease. In addition, just to increase the peculiarity of this case report, the patient had an unremarkable clinical record, and never suffered from chronic constipation in the past.