| Internal hernia | |
|---|---|
 | |
| A hernia—the hole in the light-colored wall of tissue—can trap loops of the bowel or other tissue | |
| Specialty | General surgery |
| Differential diagnosis | Endometriosis,chronic pelvic pain |
Internal hernias occur when there is protrusion of an internal organ into aretroperitoneal fossa or aforamen (congenital or acquired) in theabdominal cavity. If a loop of bowel passes through the mesenteric defect, that loop is at risk forincarceration,strangulation, or for becoming the lead point of asmall bowel obstruction.[1] Internal hernias can also trapadipose tissue (fat) and nerves. Unlike more common forms of hernias, the trapped tissue protrudes inward, rather than outward.[2]
Mesenteric defects commonly occur in trauma, such asgunshot wounds to the abdomen. In trauma victims, the defect is usually closed, sometimes with resection of the associated bowel, which may have lost its blood supply.[1] Also mesenteric defects are intentionally created in theRoux-en-Y gastric bypass procedure, being classically known as a Petersen's hernia.[3] The mesenteric defect in such cases, calledPetersen's defect, is located between the transverse colon and the mesentery of the alimentary limb (the segment of the jejunum from the jejunojejunostomy until the connection with the proximal segment of the stomach) at the level of the jejunojejunostomy.[4]
Internal hernias are difficult to identify in women, and misdiagnosis withendometriosis or idiopathicchronic pelvic pain is very common. One cause of misdiagnosis that when the woman lies down flat on an examination table, all of themedical signs of the hernia disappear. The hernia can typically only be detected when symptoms are present, so diagnosis requires positioning the woman's body in a way that provokes symptoms.
Both internal hernias andumbilical hernias are more common in women than men.[2]