Internal hernias occur when there is protrusion of an internal organ into a retroperitoneal fossa or a

foramen In anatomy and osteology, a foramen (;Entry "foramen"
in

abdominal cavity The abdominal cavity is a large body cavity in humans and many other animals that contains many organs. It is a part of the abdominopelvic cavity. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roof is the th ...

. If a loop of bowel passes through the mesenteric defect, that loop is at risk for

incarceration Imprisonment is the restraint of a person's liberty, for any cause whatsoever, whether by authority of the government, or by a person acting without such authority. In the latter case it is "false imprisonment". Imprisonment does not necessari ...

strangulation Strangling is compression of the neck that may lead to unconsciousness or death by causing an increasingly hypoxic state in the brain. Fatal strangling typically occurs in cases of violence, accidents, and is one of two main ways that hanging ...

, or for becoming the lead point of a small bowel obstruction. Internal hernias can also trap

adipose tissue Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...

(fat) and nerves. Unlike more common forms of hernias, the trapped tissue protrudes inward, rather than outward. Mesenteric defects commonly occur in trauma, such as

gunshot wounds A gunshot wound (GSW) is a penetrating injury caused by a projectile (e.g. a bullet) from a gun (typically firearm or air gun). Damages may include bleeding, bone fractures, organ damage, wound infection, loss of the ability to move part ...

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. Also mesenteric defects are intentionally created in the

Roux-en-Y gastric bypass Gastric bypass surgery refers to a technique in which the stomach is divided into a small upper pouch and a much larger lower "remnant" pouch and then the small intestine is rearranged to connect to both. Surgeons have developed several diff ...

procedure, being classically known as a Petersen's hernia. The mesenteric defect in such cases, called ''Petersen'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. Internal hernias are difficult to identify in women, and misdiagnosis with

endometriosis Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, f ...

or idiopathic

chronic pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in include ...

is very common. One cause of misdiagnosis that when the woman lies down flat on an examination table, all of the

medical sign Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

s 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 and

umbilical hernia An umbilical hernia is a health condition where the abdominal wall behind the navel is damaged. It may cause the navel to bulge outwards—the bulge consisting of abdominal fat from the greater omentum or occasionally parts of the small intestine. ...

s are more common in women than men.

References

{{reflist , 2, refs= {{cite news , author=Brody, Jane E , title=In women, hernias may be hidden agony , newspaper=St. Louis Post-Dispatch , date=18 May 2011 , url=http://www.stltoday.com/lifestyles/health-med-fit/health/jane-brody/article_7e2638ac-8959-57bb-9931-6f3aa084f3a1.html {{cite journal , vauthors=Bittner JG, Edwards MA, Harrison SJ, Li K, Karmin PN, Mellinger JD , title=Laparoscopic repair of a right paraduodenal hernia , journal=JSLS , volume=13 , issue=2 , pages=242–9 , year=2009 , pmid=19660226 , pmc=3015939 {{cite journal , author=Petersen W, title=Über Darmverschlinung nach der Gastroenterostomie , journal=Arch Klin Chir, volume=62, pages=94–114, year=1900 Hernias