Acute Appendicitis Presenting as Mechanical Small Bowel Obstruction in a Patient With Prior Abdominal Surgery: A Diagnostic Dilemma.

Acute appendicitis is a common surgical emergency. However, its atypical presentations, such as mechanical small bowel obstruction (SBO), are exceedingly rare and diagnostically challenging. This is particularly true in patients with prior abdominal surgery, where postoperative adhesion is the most clinically significant cause. We report a 31-year-old man with a history of previous open gastro-jejunostomy who presented with progressive abdominal pain, distension, vomiting, and obstipation. Initial suspicion favored adhesive SBO; however, contrast-enhanced CT revealed a distended, inflamed appendix with marked peri-appendiceal inflammation causing distal ileal obstruction, distinct from the previous surgical site. Urgent exploratory laparotomy confirmed dense adhesions tethering the ileum to the inflamed appendix, which was successfully managed with adhesiolysis, release of the entrapped ileal segment, and appendectomy. The patient recovered uneventfully. This case underscores that prior abdominal surgery should not preclude consideration of appendicitis as a possible primary cause of mechanical SBO, particularly in patients with clinical features suggestive of an inflammatory process localized to the right lower quadrant. Additionally, it highlights the pivotal role of CT in differentiating inflammatory from adhesive obstruction and emphasizes the need for prompt surgical intervention to achieve favorable outcomes.