A rare combination of intestinal invagination and Meckel's diverticulum in an adult: a case report.

Intestinal invagination is a common pathology amongst children, while it is a rare entity in adults. Invagination is responsible for only 1-3% of adult-onset intestinal obstruction. Meckel's diverticulum, on the other hand, is the most common congenital anomaly of the gastrointestinal tract. Most of them are asymptomatic; they are recognized when they complicate, and can present with diverticulitis, gastrointestinal bleeding, intestinal obstruction, perforation, or invagination. A 16-year-old male patient presented to our emergency department with abdominal pain. There was a palpable mass at the right paraumbilical region. Gas-liquid level was seen on the direct abdominal radiography. On the abdominal ultrasonography, it was reported that the mass might be a result of invagination. As the patient had extensive peritonitis findings, with the pre-diagnosis of obstruction as a result of invagination, surgery was decided. During the operation, it was observed that the invaginated ileum loop was too ischemic for reduction; therefore, the invaginated part was resected and ileoileal anastomosis was performed. Examination of the resected segment revealed the Meckel's diverticulum as causing the invagination. In conclusion, with this case, we aimed to present the role of Meckel's diverticulum as an initiating factor of ileoileal invagination, with inversion into the ileum.