Gastrointestinal Bleeding: All You Need to Know About Blood in the Stools

Symptoms of digestive tract bleeding often depend upon the site of the bleeding. If the bleeding originates from the lower colon or the rectum, bright and red blood will typically mix with the stool or coat it. While the cause of the bleeding may not always be serious, it is still important that the source is determined to assess the severity of the bleeding.

The gastrointestinal or digestive tract includes the colon or large intestine, stomach, esophagus, small intestine, anus, and rectum. Bleeding can come from any of the areas mentioned. Blood in the stools can also be caused by an ulcer on the stomach’s lining or from a possible inflammation in the colon.

In many cases, blood in the stools can appear without the person noticing it. This kind of bleeding is known as occult. Fortunately, there are many simple tests that can help detect the presence of hidden or occult blood in the stool. There are also many tests available that can help locate the primary source of the bleeding.


Stool color (which can be red or black), changes in bowel habits and the location where pain is felt can help doctors determine the area that’s affected. Consuming bismuth, iron, or foods like beets can make it seem as if there is bleeding by affecting the color of the stools. Hence, some tests may be done before a diagnosis is made.  Other symptoms that are taken into account include:

  • Coffee ground appearance of the stool
  • Stool being coated with bright red blood
  • Stool mixed with dark blood
  • Tarry or black stool


When there is blood in the stool, it is crucial that the source of the bleeding is located. In line with this, a physical examination will be carried out. The complete medical history of the patient will also be examined.

A blood count is also often done to check if the patient is anemic. The results will give doctors an idea of the extent of the bleeding or how chronic it may be. Other tests that might be recommended include:


This is a very common diagnostic procedure that allows doctors to view the bleeding site. Endoscopy can also detect lesions. More importantly, the process can confirm the absence or presence of bleeding. Often, this is recommended for those patients with acute bleeding.

Doctors are also able to use the endoscope to treat those patients with acute bleeding. Endoscopes are instruments that are inserted through the rectum or mouth so as to allow doctors to examine the rectum, stomach, esophagus, colon, and duodenum and take photographs of these areas.

Endoscopy can also be done to stop the bleeding or collect small tissue samples. Enteroscopy, also known as small bowel endoscopy, is a procedure that is performed using a long endoscope. The endoscope can also be used to localize possible unidentified bleeding sources in the small intestine.

There are also other procedures that can be done to determine the possible cause of the bleeding. For instance, another procedure called Barium X-rays can also be done. However, this test is considered less accurate compared to endoscopy when it comes to locating the site of the bleeding.

Barium X-ray also has one significant drawback — it exposes the individual to X-rays but it does not provide the capabilities of a treatment or biopsy. Another kind of X-ray that might be recommended is the CT scan.

Angiography is also an alternative procedure which makes use of dye in order to highlight the blood vessels. This technique is highly useful for those situations where there is acute bleeding as the dye will leak out of the blood vessel which allows the bleeding site to be determined. In some cases, angiography will also involve the injection of medicine into the arteries in order to stop the bleeding.