The causes of blood clots in stool – feces – can range from the mundane to the unusual. For most people, blood in stool is rare enough to warrant a visit to a doctor’s office. The primary reasons are simple: red blood in stool or (more critically) black blood in stool is a clear indicator of ulcerations or even cancers.
Blood clots are part of the body’s natural functions for healing. They form from congealed blood cells and plasma and act as a biological patch internally. Blood clots seal wounds, and normally they dissolve and are flushed away or recycled for nutrients as the body requires.
A blood clot that forms in a vessel is called a thrombus. Should such a clot break loose of its moorings, it may cause damage by blocking an artery carrying oxygen to the brain or lungs. This blockage action is called thrombosis, and death can often result from a blood clot plugging an artery or vein.
Other clots may form and dislodge without being noticed until they pass from the body in human waste. Blood clots in stool may appear as a smeary, iron-oxide tinted product not usually associated with feces.
Causes of blood clots in stool can be either from a temporary condition or a chronic ailment. The clots can be from gastrointestinal bleeding from infections (such as some strains of salmonella) or certain stomach parasites. Ulcers, of course, can also cause gastrointestinal bleeds. These are conditions that usually can be quickly corrected with medications. Any fresh blood routinely found in the stool (the bright red color) is usually an indicator of a minor problem such as internal or external hemorrhoids.
However, much more serious is a tarry or blackened blood clot found in the feces, giving it a foul smell (such blackened stool is called melena). Normally, this blackened stool results from blood originating in the stomach or upper gastrointestinal tract, and it indicates blood that has sufficiently “aged” before passing from the body. Melena can also (rarely) be an indicator of intestinal cancers, the most serious of which is colon cancer. Colon cancer starts from small growths called polyps. These are clusters of abnormally growing cells. Another cause of chronic blood clots in the stool is diverticulitis. This is when a part of the intestines twists and loops around itself or its blood vessels. This, in turn, causes a constriction; over time, this strangulated part of the intestine will lose blood flow, die off, and bleed out.
Any blood clots in stool need to be taken seriously as a warning that something is wrong with the gastrointestinal tract. One should not wait for the symptoms to “go away”. A thorough medical exam is in order; it may save one’s life.
By Bob Parker