Large bowel obstruction - sigmoid volvulus

Case contributed by RMH Core Conditions


Abdominal pain

Patient Data

Age: 92
Gender: Female

There are several distended loops of presumably large bowel projected within the central abdomen measuring up to 9 cm in diameter. Moderate to severe fecal loading is seen within the ascending and descending colon. The small amount of gas seen within the rectum. The appearances are non-specific but raise the possibility of a distal large bowel obstruction/sigmoid volvulus. Correlation with CT is recommended.

No definite free gas is demonstrated.

Severe degenerative changes of the lumbar spine with scoliosis convex to the right.

There is dilatation of the large bowel, with moderate/severe fecal loading. The cecum measures 10 cm in maximal diameter. An area of luminal narrowing at the region of the rectosigmoid junction is noted and very little rectal contrast has passed beyond this point. Adjacent to this region there is also noted to be swirling of the mesentery and superior mesenteric vessels. The caliber of the small bowel is normal. Thickening of the incompletely visualized inferior rectal wall is also noted.


Findings of large bowel dilatation and mesenteric 'swirl' is suspicious for sigmoid volvulus.

The patient went to sigmoid decompression via rectal tube. 

Contrast within the urinary bladder. Gas is demonstrated throughout both small and large bowel, to lower pelvis. There is moderate colonic fecal loading. Gas filled viscus within the left midabdomen may reflect moderate gaseous distension of redundant sigmoid. No free or portal venous gas. 

Case Discussion

Key learning points:

  • sigmoid volvulus is a common cause of large bowel obstruction
  • whirl sign of mesenteric vessels is a good clue
  • can be complicated by bowel ischemia
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Case information

rID: 31042
Published: 18th Sep 2014
Last edited: 16th Jul 2018
Inclusion in quiz mode: Included

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