The most common place for blood clots to form is in the lower leg due to decelerating blood flow to the lower limbs. Sometimes, however, a blood clot may form in the veins leading to the stomach. This potentially life-threatening complication could produce specific signs when going to the toilet.
The splenic, superior or inferior mesenteric veins all deliver nutrient-rich blood to the liver through the hepatic portal vein.
When a blood clot forms in these veins it prevents blood flow to the intestines, which can lead to the damage or death of tissue in this organ.
Blood clots that form in the stomach or abdominal area are medically recognised as a type of deep vein thrombosis called mesenteric venous thrombosis (MVT).
MedlinePlus defines MVT as a “blood clot in one or more of the major veins that drain blood from the intestine”.
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“The superior mesenteric vein is most commonly involved.”
As the venous return of the bowel becomes impaired, it’s natural to expect symptoms when going to the toilet.
Abdominal pain, bloating, bloody stool, and diarrhoea are common symptoms of MVT.
The mechanisms by which mesenteric venous thrombosis causes diarrhoea are related to swelling of the bowel wall, causing congestion from impaired venous drainage.
Ignoring these symptoms could be dangerous, as delayed treatment of the condition can result in life-threatening intestinal infarction.
Unfortunately, however, the condition is not easy to diagnose.
The most common symptom to arouse concern in patients is acute abdominal pain, but many cases develop asymptomatically.
This discomfort, often described as dull pain around the navel area, is a sign that blood flow in the intestine is starting to falter.
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The pain caused by blood clots in the bowel comes on quickly but sometimes develops slowly over the course of weeks or months.
Another important characteristic of this pain is that it won’t intensify when a doctor pushes on the abdominal area, as pain from appendicitis or diverticulitis would.
Moreover, it tends to be more pronounced after eating a meal, according to Medline Plus.
While the exact causes for these thrombotic events are unknown, many potential triggers have been identified.
The risk factors for MVT are generally the same as those for deep vein thromboses, such as surgery and sedentary behaviour.
Additional risk factors, however, may include digestive ailments that trigger swelling of the tissues surrounding the intestines.
For example, injury to the abdominal area, inflammatory bowel disease or cancers of the digestive system, could all lead to clotting events.
People who use hormone therapies or use contraceptive medication like birth control pills could also be at a heightened risk for such complications.