Volvulus

Malrotation of a segment of intestine about its own mesenteric axis

Results in

1. Partial / complete obstruction of lumen + proximal dilation
2. Compromise of blood flow leading to ischaemia
3. Infarction from venous congestion

Pre-disposing factors

1. Anatomy - long narrow-based sigmoid mesentry prone to twisting
2. High residue diet
3. Chronic constipation 

Areas affected

1. Small bowel
2. Caecum
3. Sigmoid colon (75%)

Management

1. History
2. Examination
3. Investigations
   • AXR - dilated loops of bowel extending diagonally
   • ABG - acidosis, lactate
4. Treatment
   • Conservative: if no features of ischaemia (80% will resolve)
   • Sigmoidoscopy - diagnostic and therapeutic
   • Flatus tube insertion (can be left for 2-3 days)
   • Laparotomy for decompression (untwisting) with excision of redundant sigmoid colon (sigmoid colectomy + primary anastamosis)