Case Presentation: An 82 year old female with history of perforated appendicitis with open appendectomy at age 15, presented with 3 years of episodic abdominal pain and distention associated with nausea and vomiting. Prior episodes had resolved on a clear liquid diet, but the current episode required admission for refractory vomiting and pain. CT abdomen initially identified a fecolith and distal small bowel wall thickening suggestive of ileitis. With GI and surgery consulting, she was managed conservatively and had symptomatic improvement. She underwent colonoscopy revealing normal distal ileum, and ileal biopsies were negative for inflammation. Further review of her abdominal CT with radiology raised the possibility of Meckel’s diverticulum containing a fecolith in the region of obstruction. The patient was subsequently discharged and underwent elective laparoscopic surgery two weeks later confirming Meckel’s diverticulum in the distal ileum as the source of obstruction. Further inspection revealed an abnormality in the mesentery supplying this area of small bowel. The diverticulum was resected with a 5cm segment of ileum on either side, with primary anastomosis of the remaining small bowel. The patient had an uneventful post-operative course and full recovery with no further symptoms.

Discussion: Meckel’s diverticulum is the most common congenital abnormality of the gastrointestinal tract, occurring in approximately 2% of the population. It is a true intestinal diverticulum that results from the failure of the vitelline duct to obliterate during early fetal development. Ninety percent of diverticula are within 90 cm of the ileocecal valve. Meckel’s diverticula contain ectopic tissue in 55% of cases, most commonly gastric mucosa and pancreatic tissue.  Results of the largest published case series on complicated Meckel’s diverticula estimated the lifetime risk of developing complications at 4.2%. Despite the belief that the incidence of complications decreases with age, two long term observational studies found an even age distribution in patients with complications. Major complications are hemorrhage, obstruction, intussusception, diverticulitis, and perforation. Bleeding is the most common complication in children, resulting from heterotopic gastric mucosa leading to ulceration. Most adults present with obstruction or diverticulitis. Small bowel obstruction may be caused entanglement of a loop of small bowel around a fibrous band or within a mesodiverticular band, intussusception, volvulus, incarceration within a hernia sac, chronic diverticulitis, foreign body/enterolith, or neoplasm. Abdominal plain films or upper GI series are rarely helpful, although CT scans can occasionally be diagnostic, as was illustrated in our case. The most useful method of detection is technetium-99m pertechnetate scanning; however, the technetium scan depends on uptake by heterotopic gastric mucosa which is not present in all diverticula. The scan has a sensitivity of 85% and a specificity of 95 % in children, but in adults, sensitivity falls to 62.5% and specificity to only 9%. Definite management of symptomatic diverticula is surgical resection, but controversy remains as to appropriate management for incidentally identified, asymptomatic diverticula.

Conclusions: Meckel’s diverticula should be considered in the differential for adult patients presenting with small bowel obstruction, particularly in those lacking other risk factors for obstruction.