Unusual Differential Disease Entity of Right Lower Abdominal Pain, Ileal Diverticulitis Perforation: A Report of Three Cases

Introduction: Small bowel diverticulum is a rare disease entity, and most cases are asymptomatic. However, diverticulitis can cause acute abdomen conditions like colonic diverticulitis. Depending on the location, various abdominal symptoms may ensue. Clinical manifestations of ileal diverticulitis may be similar to those of appendicitis and or colonic diverticulitis. Thus, making a diagnosis based on a physical examination alone may be challenging. Even though imaging techniques such as computed tomography (CT) may provide clues for a definite diagnosis, the majority of cases are confirmed through operation. Here, we present 3 cases of ileal diverticulitis perforation, which were not diagnosed preoperatively. Case presentation: A 71-year-old man, a 77-year-old woman, and a 78-year-old woman presented with abdominal pain. All 3 patients showed local peritoneal irritation signs in the right lower quadrant. Appendicitis or colonic diverticulitis was suspected, but CT scan results revealed free air and mesenteric fat infiltration around the terminal ileum, suggesting ileal perforation. During the operation in each case, terminal ileal perforation was confirmed, and ileocecal resection was performed. Subsequently, histologic examination revealed ileal diverticulitis perforation. Although the postoperative course was uneventful in the first and second patient, the third patient died of sepsis resulting from anastomosis leakage. Conclusion: These cases put forth unusual causes of right lower quadrant pain, which show physical findings similar to those of diverse inflammatory disease. Awareness of this disease is beneficial for making a differential diagnosis based on CT findings and eliciting prompt surgical management.