In a strangulated hernia, the blood supply of the contents of the hernia, e.g. bowel or omentum, is cut off. It is commonest at the neck of the sac. The region becomes ischaemic and subsequently gangrenous. Gangrene can lead to perforation of the bowel with ensuing peritonitis.
When a loop of gut is strangulated, there will also be intestinal obstruction.
Last reviewed 01/2018