Various causes can be behind blood in the stool (hematochezia): While bright red blood usually indicates hemorrhoids or anal fissures, occult blood can be a sign of colon cancer. Occult blood is hidden blood that can only be detected in the stool by a stool test. We explain what causes may underlie your symptoms and what treatment options are available for blood in the stool.
Causes of blood in stool
Although many sufferers think directly of colon cancer when they see blood in the stool, this is only one of many possible causes. Often the bleeding has a completely different, more harmless reason. The following is a list of the most common causes in the anal area:
- Hemorrhoids
- Anal fissure
- Anal vein thrombosis
- Anal fistula
- Anal margin cancer
The most common causes in the small intestine, colon and rectum are:
- Diverticula
- Polyps
- Angiodysplasias (malformations of the blood vessels).
- Partially chronic inflammation (such as Crohn’s disease or forms of colitis).
- Vascular problems of the intestine
- Colon cancer
- Cancer of the rectum
- Rectal ulcers
In addition, the cause of the bleeding may also be in the upper gastrointestinal tract:
- Gastric ulcer
- Injuries of the gastric mucosa or mucosal ruptures
- Varicose veins of the esophagus (esophageal varices).
- Stomach cancer
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Black blood in the stool
If a black-colored tarry stool occurs, the cause is usually bleeding in the upper digestive tract. It is often caused by a stomach ulcer or varicose veins in the esophagus, but it can also be due to inflammation in the upper digestive tract. The blood turns black due to contact with stomach acid.
Bright red blood in stool
Bright blood deposited on the stool usually indicates bleeding in the anal region. The cause of such bleeding is often hemorrhoids. Hemorrhoids are nodular enlargements that lie above the sphincter muscle. Together with the sphincter muscle, they ensure that the anus is sealed. In addition to hemorrhoids, bright red blood on toilet paper or in stool also occurs with anal fissures. These tears in the mucous membrane of the anus often become noticeable during constipation, when those affected have to push hard during bowel movements. In addition, patients with chronic inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis suffer more often from anal fissures.
Colorectal cancer: occult blood in the stool
Bright red blood in the stool is not necessarily a sign of colorectal cancer. In the case of colorectal cancer, the blood in the stool is in fact often only discovered by a stool blood test (hemoccult test). This can detect blood residues in the stool that are not visible to the naked eye. These residues are called occult blood, which is why the test is also called an occult blood test. For a long time, colorectal cancer is not noticeable, or at most only with non-specific symptoms. In addition to blood and mucus in the stool, these can include abdominal pain, persistent constipation or diarrhea, and severe flatulence. Such symptoms should therefore always be clarified by a doctor to be on the safe side. More information on signs of colorectal cancer can be found here.
Blood in diarrhea
If blood is present in the stool during diarrhea, various causes are also possible. However, a temporary viral or bacterial infection is particularly often behind the complaints. But a chronic inflammation of the intestine can also be the trigger. For example, bloody diarrhea occurs more often in ulcerative colitis patients.
Blood in the stool in babies and children
In babies and children, blood in the stool usually has the same causes as in adults. Polyps or anal fissures are particularly often responsible for the bleeding. In babies who suffer from constipation, the tears are caused by heavy pressing during bowel movements. In addition to anal fissures, blood in the stool in babies can also indicate an allergy to cow’s milk. This form of allergy occurs in about two to seven percent of all children. If your baby suffers from bloody diarrhea, a bacterial infection may also be the trigger. If the symptoms are severe or persist for a long time, you should always consult a doctor and have the cause clarified in order to rule out a chronic intestinal disease.
Which doctor helps with blood in the stool?
If you notice blood in your stool, you should always consult a doctor. The right contact person here is first of all the family doctor. This can refer you to a specialist, such as a gastroenterologist or proctologist, if necessary. To find the cause of the bleeding, a palpation is often sufficient, but sometimes a gastroscopy or colonoscopy is also necessary. Nowadays you don’t have to be afraid of these examinations, due to appropriate medication you will hardly notice anything of the examination. The aim of the examinations is to find the source of the bleeding and to stop it. This is especially important if the bleeding is severe, such as in the case of a stomach ulcer. However, even with minor bleeding, anemia can develop over time due to the constant loss of blood.
Treatment depends on cause
What treatment is needed depends on the cause behind the blood in the stool:
- Hemorrhoids: Depending on the size of the hemorrhoids, they can be treated initially with ointments or suppositories. Larger hemorrhoids must be sclerosed or completely removed.
- Anal fissures: many fissures can be treated with ointments or suppositories. An anal dilator can also be helpful here. In some cases, however, surgery is inevitable.
- Bacterial infections: Such infections can be treated with appropriate medication, often antibiotics.
- Chronic intestinal diseases: Here, treatment is carried out with specific drugs.
- Intestinal polyps or intestinal diverticula: These are removed surgically – usually by means of endoscopy.
- Colorectal cancer: In colorectal cancer, treatment depends on the stage of the tumor. Treatment options include chemotherapy, radiotherapy or surgery.
Blood in the stool is therefore usually no cause for alarm and the trigger can often be easily treated. Nevertheless, the cause of blood in the stool should always be clarified by a doctor to exclude more serious diseases and to be able to treat early in an emergency.
