Acute mechanical bowel obstruction: Clinical presentation, etiology, management and outcome

Aim: To identify and analyze the clinical presentation, management and outcome of patients with acute mechanical bowel obstruction along with the etiology of obstruction and the incidence and causes of bowel ischemia, necrosis, and perforation. Methods: This is a prospective observational study of all adult patients admitted with acute mechanical bowel obstruction between 2001 and 2002. Results: Of the 150 consecutive patients included in the study, 114 (76%) presented with small bowel and 36 (24%) with large bowel obstruction. Absence of passage of flatus (90%) and/or feces (80.6%) and abdominal distension (65.3%) were the most common symptoms and physical finding, respectively. Adhesions (64.8%), incarcerated hernias (14.8%), and large bowel cancer (13.4%) were the most frequent causes of obstruction. Eighty-eight patients (58.7%) were treated conservatively and 62 (41.3%) were operated (29 on the first day). Bowel ischemia was found in 21 cases (14%), necrosis in 14 (9.3%), and perforation in 8 (5.3%). Hernias, large bowel cancer, and adhesions were the most frequent causes of bowel ischemia (57.2%, 19.1%, 14.3%), necrosis (42.8%, 21.4%, 21.4%), and perforation (50%, 25%, 25%). A significantly higher risk of strangulation was noticed in incarcerated hernias than all the other obstruction causes. Conclusion: Absence of passage of flatus and/or feces and abdominal distension are the most common symptoms and physical finding of patients with acute mechanical bowel obstruction, respectively. Adhesions, hernias, and large bowel cancer are the most common causes of obstruction, as well as of bowel ischemia, necrosis, and perforation. Although an important proportion of these patients can be nonoperatively treated, a substantial portion requires immediate operation. Great caution should be taken for the treatment of these patients since the incidence of bowel ischemia, necrosis, and perforation is significantly high.