The most frequent complication of hernias is their entrapment (incarceration). It is manifested by strong strangulation of hernial content by the hernial aperture. Strong, instant pain  appears, hernia increases its volume, there is nausea, vomiting, retention of gases and feces. Intestinal obstruction picture develops. If no operation is undertaken instantly and if the intestine is entrapped, intestinal necrosis appears with efflux of intestinal content into the abdominal cavity and the result is peritonitis.

Traumatic injuries of hernial content is noticed often too.

Entrapped small intestine in inguinal hernia, laparoscopic view

Defect and hernial ring are seen after release of intestine, laparoscopic view