Introduction
If one discovers blood in the stool, one should not immediately fear the worst. Although the cause can also be malignant, harmless causes are much more common. A doctor should be consulted to find out the cause of the blood admixture.
Causes
Among the causes that cause blood in the stool are among others:
- Haemorrhoids and ruptured mucous membranes
- Stomach Ulcers
- Diseases of the esophagus
- For diarrhoea
- Taking antibiotics
- Intestinal diseases
- Vascular causes
Hemorrhoids and anal tears are the two most common causes of bloody stools. Hemorrhoids are the most common cause of finding blood in stool. In this case it is very fresh blood, which can be seen in the stool and often leaves its mark on the toilet paper.
Haemorrhoids are more common in people over 50. They are dilated vascular cushions, which normally contribute to stool continence in the non-dilated state. In a healthy state they are located at the transition from the rectum to the anal canal.
If they are enlarged, however, they may also be visible from the outside. Due to the increased pressure during bowel movement, they can tear open and lead to fresh bleeding. Many factors can be the cause of haemorrhoids.
Often there is an accumulation in the family. An important risk factor is high pressure inside the abdomen and during bowel movements. This occurs, for example, during long periods of sitting, in cases of severe overweight, frequent constipation, heavy pressing during bowel movements, low-fibre nutrition or during pregnancy.
Small tears in the mucous membrane (fissures) in the area of the anus can occur in connection with constipation if the person concerned has to press hard during defecation so that the mucous membrane cannot withstand the pressure in the long term. Bleeding stomach ulcers (gastric ulcer) are often responsible for tarry stools. Many people develop a gastric ulcer due to high alcohol or nicotine consumption, chronic stress or long-term use of painkillers that attack the stomach lining.
With these painkillers, it is important to take a stomach protector such as a proton pump inhibitor at the same time when taking them for a longer period of time. Gastritis (inflammation of the stomach lining) caused by the bacterium Helicobacter pylori can also lead to a gastric ulcer. An ulcer can not only develop in the stomach, but also in the following section, the duodenum.
Blood in the stool can also be associated with chronic inflammatory bowel disease, including Crohn’s disease and ulcerative colitis. Both diseases manifest themselves primarily with intermittent phases of diarrhoea. Particularly in ulcerative colitis, these diarrhoea episodes can often be bloody.
An emergency case of stool in the blood is bleeding due to ruptured varicose veins in the oesophagus, the so-called oesophageal varicose vein bleeding. They can lead to life-threatening bleeding. The varicose veins develop in connection with chronic liver diseases in which the blood can no longer flow through the liver, but has to find alternative routes, including via vessels in the oesophagus.
Another disease of the oesophagus is Mallory-Weiss syndrome. It occurs more frequently in alcoholics, in whom the mucous membrane is increasingly damaged. If vomiting then occurs, the pressure in the oesophagus rises, which can lead to bleeding tears in the previously damaged mucous membrane.
The consistency of the stool is finely regulated by various processes within the intestinal mucosa. If diarrhoea occurs, it is often a temporary problem of the intestinal mucosa. This represents the innermost wall of the intestine and can be inflamed by pathogens, certain foods, harmful substances, stress and diseases of the body.
The most common cause of a disease known in common parlance as “gastroenteritis” is bacterial pathogens that enter the intestine via food or through inadequate hygiene. As a result, the mucous membrane is no longer able to absorb the fluid from the stool and diarrhoea occurs. Sometimes the inflammation of the mucous membrane can become so severe that minor injuries and tears of the mucous membrane occur, which become noticeable as blood in the stool.
The high amount of stool that passes through the intestines in the course of a diarrhoea illness can also lead to cracks and small bleedings of the intestinal walls. In rare cases, blood in the stool can be a side effect of taking antibiotics. In particular, if diarrhoea occurs at the same time, smaller amounts of blood in the stool are likely.
An inflammation of the gastrointestinal mucosa causes small tears and damage to the intestinal wall from which it can bleed. If the blood is excreted with the stool, it is already clotted and therefore usually has a darker colour. In rare cases, taking antibiotics can temporarily aggravate the infection.
This is the case, for example, when the bacterium releases toxins. When the antibiotics attack the bacteria, large amounts of the toxins are suddenly released, which can cause the infection and the blood in the stool to get worse. Taking antibiotics for a very long time can in turn promote intestinal infections.
A relevant complication of long antibiotic intake is the Clostridium difficile infection, also called pseudomembranous colitis. This topic might also be of interest to you: Side effects of antibioticsIn older patients, the occlusion of an intestinal vessel, a mesenteric artery occlusion, can also cause bleeding. Due to the occlusion of the blood vessel, a part of the intestine cannot be supplied with oxygen and nutrients, which causes this part of the intestine to die permanently, which in turn can lead to bleeding.
In addition, altered blood vessels, an inflammation of the blood vessels (vasculitis), as well as an increased tendency to bleed are also possible causes. In addition to the largely harmless causes of blood in the stool mentioned so far, stomach cancer or intestinal cancer can also be the cause of bloody stools. For this reason, the attending physician will also ask for a family history of colorectal cancer during the clarification discussion, since in this case the patient’s own colorectal cancer risk is increased.
Since intestinal cancer usually only occurs in people over 50, free intestinal cancer screening is offered from the age of 50 onwards. Besides bowel cancer, benign tissue growths, the so-called intestinal polyps, can also be the cause of blood in the stool. Likewise, protrusions of the intestinal wall – diverticula – can cause bleeding.
Polyps and diverticula usually occur in the colon and in older patients. Stress can have a considerable influence on the body and its health. Besides many cardiovascular diseases, stress can also influence the immune system and cause blood in the stool in many ways.
Very common is the so-called “stress ulcer”. Excessive stress increases the production of stomach acid, which can lead to acid-related inflammation of the oesophagus and stomach. An ulcer is very painful and can sometimes cause heavy bleeding from the mucous membrane, which is noticeable as clotted, dark blood in the stool.
Stress also affects the immune system and can weaken it, making stressed persons more susceptible to infections. If there is fever, diarrhoea and blood in the stool, there is primarily the suspicion of a gastrointestinal infection, which can be promoted by stress. This topic may also be of interest to you, as stress ulcers are usually preceded by heartburn.
For example, salmonella, shigella, E. coli or even parasites can trigger a gastrointestinal infection with bloody diarrhoea and vomiting. In this case, the mucous membrane of the uterus is carried over into other organs. Although the intestine is not the most typical site for this, it can also be affected and lead to bleeding.
During pregnancy, haemorrhoids can occur more frequently, which are usually the cause of blood in the stool in pregnant women and the rest of the population. Haemorrhoids occur in pregnant women mainly in the last third of pregnancy and in the first weeks after the birth of the child. The increased occurrence of haemorrhoids during pregnancy can be explained by the altered hormonal balance of a pregnant woman.
The hormones cause the tissue to become soft and the vessels to dilate, thus preparing the body for the coming birth. The effect is also felt in the rectum, thus increasing the risk of developing haemorrhoids. Constipation also occurs more frequently during pregnancy.
Approximately half of all pregnant women have to deal with them. The hormones are also responsible for this, as is the increased pressure of the uterus on the rectum. The constipation promotes the development of anal fissures (tears in the anal mucosa).
In any case a doctor should be consulted for clarification. In most cases, however, there is no reason for concern. Blood in the stool does not always have to be accompanied by pain.
Both infections and chronic inflammatory bowel diseases can take a painless course. Even haemorrhoids, which in many cases are responsible for fresh blood in the stool, only rarely hurt. In rare cases, if intestinal cancer is behind the blood in the stool, pain is also a rare accompanying symptom. Bowel cancer is known to cause pain rarely and in very late stages. The accompanying symptom of pain when there is blood in the stool is therefore of little significance for the type and prognosis of the underlying disease, which is why a clarification by the doctor is advisable in all cases.
