Small Bowel Volvulus

Small bowel volvulus is twisting of small intestine and its mesentery around a vascular axis, producing mechanical obstruction with potential rapid strangulation.

It may be primary, without an identifiable anatomical lesion, or secondary to adhesions, congenital bands, malrotation, internal hernia, tumour or other fixation points.

The danger is mesenteric vascular occlusion and extensive small bowel infarction.

Presentation is usually abrupt with severe colicky or continuous central abdominal pain, vomiting and distension.

Pain may be disproportionately severe early when vascular compromise develops.

Persistent tachycardia, focal tenderness, gastrointestinal bleeding, guarding, metabolic acidosis or shock suggest strangulation.

Obtain full blood count, renal function, electrolytes, blood gas and lactate. Normal lactate does not exclude early bowel ischaemia.

CT abdomen and pelvis with IV contrast: look for twisting of mesenteric vessels and bowel around the mesenteric axis, classically the whirl appearance, with assessment of bowel enhancement. EAST specifically recommends CT in suspected small bowel volvulus.

Small bowel volvulus requires urgent surgical assessment. Suspected ischaemia, peritonitis, closed loop obstruction or physiological deterioration requires immediate exploration.

Resuscitate with balanced crystalloid, nasogastric decompression and correction of electrolytes while arranging surgery.

When ischaemia is suspected, give:

Ceftriaxone 2 g IV every 24 hours plus metronidazole 500 mg IV every 12 hours, or broader therapy for severe sepsis.

At surgery, detorse the bowel when viable and identify the underlying cause. Divide congenital or adhesive bands and close internal hernia defects.

When malrotation is responsible, definitive correction requires a Ladd procedure rather than detorsion alone.

Clearly necrotic bowel requires resection. Preserve maximum viable small bowel because extensive resection risks short bowel syndrome and intestinal failure.

If a large length of bowel appears marginal after detorsion, reassess after warming and reperfusion. A planned second look operation can prevent unnecessary massive resection while ensuring evolving necrosis is not missed.