Mesenteric venous thrombosis is a blood clot in the major veins that drain blood from the intestine.

Mesenteric venous thrombosis affects the mesenteric veins, one of two veins through which blood leaves the intestine. The condition interrupts blood supply to the intestine and can result in intestinal damage.

There are a variety of causes of mesenteric venous thrombosis. Many of the diseases that lead to this condition cause inflammation of the tissues surrounding the veins. The following conditions can lead to inflammation and mesenteric venous thrombosis:

• Pancreatitis
• Diverticulitis
• Appendicitis (less common)
• Liver disease with cirrhosis

Patients who have blood clotting disorders that make the blood more likely to stick together (clot) have a higher risk for mesenteric venous thrombosis.

In most cases, mesenteric venous thrombosis is a condition that slowly gets worse. Symptoms include long-term abdominal pain, which may get worse after eating. Sudden (acute) mesenteric venous thrombosis can cause severe abdominal pain that continues to get worse. The patient may also have vomiting and diarrhea.

A CT scan is the main test used to diagnose mesenteric venous thrombosis. An ultrasound of the abdomen and mesenteric veins may also be done.

Blood thinners are used to treat mesenteric venous thrombosis. Heparin is the most commonly used drug. In some cases, medicine to dissolve the clot can be delivered directly into the clot itself. This procedure is called thrombolysis.

If the patient has signs and symptoms of peritonitis, surgery is usually needed to remove intestine. At times, an ileostomy or colostomy may be necessary.

How well a person does depends on the cause of the thrombosis. Getting treatment for the underlying cause before the intestine has died can result in a good recovery.

A serious complication of mesenteric venous thrombosis is intestinal ischemia, in which some or all of the intestine dies because of poor blood supply.

Call your health care provider if you have severe or repeated episodes of abdominal pain.