Congenital mesenteric defects can lead to internal hernias which may result in a bowel obstruction. They are very rare among the adult population, comprising only 0.2%-0.9% incidence rate of all small bowel obstructions. A 40 year old woman presented to the Emergency Department with abdominal pain.Computed tomography scan was obtained and showed a small bowel obstruction.After failed conservative management with bowel rest and nasogastric tube decompression, the patient underwent diagnostic laparoscopy.An internal hernia was identified though a congenital mesenteric defect at the level of the sigmoid colon. The hernia was reduced and the defect closed. When a patient presents with abdominal pain the diagnosis of a congenital mesenteric defect with internal hernia should be considered with subsequent emergent surgical exploration.