Caecal Bascule Volvulus: Diagnostic Challenges in a Rare cause of Large Bowel Obstruction.

Caecal bascule is the rarest form of caecal volvulus, representing 5%-20% of caecal volvulus cases and accounting for 0.2% of intestinal obstructions. Diagnosis can be delayed due to non-specific clinical and radiological features, increasing the risk of ischaemia or perforation. Herein, we report the case of a 70-year-old woman who presented with vague right iliac fossa (RIF) pain, nausea and bilious vomiting. Computed tomography (CT) of the abdomen and pelvis demonstrated a mesenteric 'whirl sign' concerning for a volvulus. Emergency laparoscopy demonstrated a distended caecum (C) folded anteriorly without torsion, consistent with caecal bascule. A right hemicolectomy with primary anastomosis was performed. The postoperative course was complicated by a small non-drainable collection, managed conservatively with antibiotics. Histopathology showed mild vascular congestion with normal architecture and no ischaemia, malignancy or inflammatory bowel disease. This case highlights the diagnostic challenge of caecal bascule and the importance of timely surgical intervention.