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Blood in the stool


Blood in stool (med .: hematocheia, melena) is seen by most patients as something terrible. Noticing the blood in stool, do not be afraid of the worst, but you should immediately go to the doctor. Possible causes of blood in the stool may be gastrointestinal infections, polyps of the large intestine or hemorrhoids, as well as gastric ulcer or chronic inflammatory disease of the large intestine. To exclude the diagnosis of malignant diseases – such as bowel cancer - it is necessary to immediately carry out relevant studies in the clinic. Below you will learn all the important information about the symptom “blood in stool”.

Blood in stool: Description

Blood in the stool indicates that the body somewhere in the gastrointestinal tract loses blood, which is then found mixed with a stool. The color and consistency of the mixed blood can serve as an almost reliable indication of the source of the bleeding.

Blood in the stool does not necessarily occur as a bright red or dark red plaque or impurity, in fact it can stain the stool black. The corresponding manifestations in this case depend on the height of the bleeding in the digestive tract, as the blood state changes upon contact with gastric juice and as a result of processing by microorganisms.

Red blood in stool (hematochezia)

If the blood in the stool is in the form of bright red or dark red, in the form of an impurity or strips, then the blood is relatively fresh. This type of blood in the stool is called hematochezia. The source of bleeding is most likely in the middle or lower parts of the gastrointestinal tract (GIT), because the blood could not be destroyed in large quantities by hydrochloric acid of the stomach, or bacteria.

If stool is evenly colored in a dark red color, this can indicate, for example, large bleeding in the large intestine. With small bleeding in the stool, jelly-like traces of blood are observed.

In turn, the light red bands may indicate a fresh bleeding in the rectum, for example, with hemorrhoids.

Black blood in the stool (melena, tarry stool)

If stool is black and shiny, then we are talking about the so-called tarry stool (melena). In cases of bleeding in the upper gastrointestinal tract, that is, from the esophagus to the duodenum, hemoglobin in the blood, upon contact with gastric juice, decomposes to hematin. This hematin is the reason for the black color of the stool, and in the case of vomiting, the vomiting mass may resemble coffee grounds.

Black stool often indicates that the source of bleeding is above the small intestine and is caused by either a stomach ulcer or bleeding in the esophagus.

Since intestinal bacteria with prolonged exposure to blood also cause the breakdown of hemoglobin into the pigment of hematin, the black color of the stool may not necessarily be a consequence of bleeding in the upper gastrointestinal tract. With delayed passage of chyme (contents of the intestine), melena may cause bleeding, located deeper.

Under certain circumstances, high-located bleeding in the gastrointestinal tract, on the contrary, can lead to hematochezia, both with a decrease in the secretion of gastric juice due to medication, and with severe bleeding, when the chyme quickly passes through the intestine.

Hidden blood in stool

It may also be that, despite the fact that the blood in the stool is present, it is not visible. Then it's about hidden blood. In most cases, it is detected accidentally in a routine examination or in a targeted study with a known damage to the digestive tract.

Since blood cannot be detected with the naked eye, a guaiacol test for detecting blood in the stool (hemoccult test) is used, with which it can be detected even in small amounts.

Cases that are confused with the presence of blood in stool

After eating certain foods, the feces may look as if there is blood in it. This leads to the use of red beets, staining the stools in a dark red color, which occurs during hematochezia. Bilberry stains a chair in black, similar to licorice, so that when viewed it is perceived as melena.

In addition, some medications may give a black color to the stool (for example, activated charcoal or iron preparations).

Blood in stool: causes and possible diseases:

Various possible causes of the appearance of blood in the stool are considered, which cause bleeding in the gastrointestinal tract. These include bleeding from the oropharynx, esophagus, stomach, small and large intestine and anus. In principle, bleeding can occur in each department, and the frequency and significance of various causes vary.

Blood in stool with bleeding in the upper parts of the gastrointestinal tract

  • Most often, the cause of bleeding in the upper parts of the gastrointestinal tract is ulcers in the stomach and duodenum, often caused by Helicobacter pylori bacteria or the prolonged intake of certain medications, such as, for example, aspirin.
  • Chronic heartburn can lead to inflammation of the esophagus (reflux-esophagitis) and, consequently, to bleeding when gastric juice gets into the stomach.
  • With certain diseases of the liver, there is a redistribution of venous blood flow, which causes varicose veins of the esophagus. Such dilated veins are easily torn and lead to severe, often life-threatening bleeding.
  • After profuse vomiting, there may be prolonged tears in the mucous membrane at the site of the esophagus into the stomach. Then we are talking about the Mallory-Weiss syndrome, often found in alcoholics who previously had a damaged mucous membrane.
  • In conclusion, blood in stool can also be a likely symptom for stomach cancer.
  • In the middle parts of the gastrointestinal tract, the most common cause of bleeding is small intestinal tumors. In the large intestine, atypical growths can lead to the appearance of blood in stool. They do not need to be malignant.
  • Especially in young patients, chronic inflammatory intestinal diseases, such as Crohn’s disease or ulcerative colitis, can cause bleeding. If in the latter case only the large intestine and rectum are affected, then in Crohn’s disease [the whole gastrointestinal tract] can be affected. The exact causes of both diseases are unknown.
  • Polyps are more often benign outgrowths of the large intestine, which usually do not cause any problems, but as the size increases, the risk of bleeding also increases. They can also develop into precancerous conditions, so that, starting with a certain size; they are mainly to be removed. The consequence of such interventions in turn may be secondary bleeding.
  • With diverticula, it is a question of protrusion of the walls of the intestinal wall, which, if viewed from the inside, are small “pits”. Diverticula are formed and found in the large intestine. Depending on the circumstances, they can become inflamed (then it comes to diverticulitis) and cause bleeding.
  • Various infectious diseases of the intestine, ranging from ordinary gastroenteritis to severe diseases like typhoid or dysentery, can be the cause of blood in the stool, most often in combination with proliferation. In addition, excessive reproduction of bacteria that make up the natural intestinal microflora, for example, after [course] of antibiotic therapy, can cause hematochezia. An example is pseudomembranous colitis.
  • Bright red blood in the stool often occurs with hemorrhoids. This usually implies a pathological increase in arteriovenous anastomoses under the mucosa of the rectum. When defecating, they are often damaged, which leads to a touch of fresh, often bright red blood.
  • In senior citizens, there are often so-called mesenteric infarcts, that is, blockage of the vessels of the intestine. If the tissues of the affected areas are damaged, subsequent bleeding may occur.

Blood in stool with bleeding in the middle and lower parts of the gastrointestinal tract

Blood in stool: When should you see a doctor?

If you have found blood in your stool, you should see a doctor in any case. Despite the fact that most bleeding stops without medical assistance on their own and that often does not pose a threat. Still, it is necessary to find out where the source of bleeding is and whether there is a more serious disease behind it. Especially when there are other symptoms – for example, when:

  • Pain in the stomach and abdomen.
  • Pain during defecation
  • Nausea and vomiting (including when there is blood in the vomiting mass)
  • Prolonged lethargy and fatigue
  • Pronounced weight loss in a short time
  • Night sweats

Do not postpone the visit to the doctor

With severe bleeding in the gastrointestinal tract after a certain period due to blood loss, anemia may occur, which in any case requires treatment.

Blood in stool: What does the doctor do?

If blood in stool is caused by acute bleeding in the gastrointestinal tract, which caused severe blood loss, first of all it is necessary to compensate for the missing volume of blood. In the absence of treatment, this in the worst case can lead to hypovolemic shock – a life-threatening condition.

The patient is placed in the supine position, receives oxygen through the nasal probe and as soon as possible – a blood substitute, to replenish lost blood volumes. With large blood loss, blood transfusion is also performed.

In addition, with chronic bleeding in the gastrointestinal tract for a long time, anemia may develop, the treatment of which is similar [to the treatment of acute blood loss]. 

Anamnesis and examination

If the patient seeks a doctor with complaints of blood in stool, in most cases the place of bleeding is unknown and should be established.

Data from the medical history can give valuable guidance. For example, it may be important whether blood was previously in stool. It should be clarified whether there were previously hemorrhoids, peptic ulcer disease, chronic inflammatory bowel disease, alcohol abuse or diverticula, that is, whether there are risk factors for gastrointestinal bleeding. Further investigations are carried out to find the source of bleeding.

  • In this case, great importance belongs to gastroendoscopy, in which the gastric tube (gastroenteroscope) is inserted through the mouth and allows the doctor to evaluate the condition of the esophagus, stomach and duodenum by means of an endoscope. When examining the large intestine (a coloscopy), the endoscope is inserted into the rectum and can be introduced up to the final section of the small intestine. With the help of these examination methods, many possible causes such as diverticulum, chronic inflammation, ulcers, esophageal varices, polyps of the large intestine and other sprouting can be found. For the examination of hemorrhoids, rectoscopy is most often used. Although nature of blood in stool, as well as the possible previously established diseases and can indicate the position of the source of bleeding, it is still better to use gastroduodenoscopy, especially in those cases where a particular lesion cannot be established.

Since gastroduodenoscopy may not always show a source of bleeding and, besides, it is not always possible to obtain sufficient data, then in such cases additional methods of examination are used.

  • Double balloon enteroscopy allows you to examine the state of the small intestine. In this case, two balloons attached to the endoscope are alternately inflated, so that they can be advanced by the length of the endoscope. This examination is usually performed in two stages – the examination of the upper part of the small intestine with the introduction of the probe through the mouth, the lower – through the anus.
  • Meanwhile, there is also the possibility of video capsule endoscopy. In this case, the patient swallows the mini-camera, which takes pictures at regular intervals. Thus, the small intestine is examined. Nevertheless, this method takes time and does not allow to establish the exact localization of the source of bleeding.
  • With the help of ultrasound, it is possible to detect obstruction of blood vessels as a possible cause of blood in the stool.
  • Further, nuclear medical techniques and selective arteriography that can detect only active bleeding can be used.
  • If you suspect that the cause of blood in the stool is an infection – an attempt is made to determine the appropriate pathogens with the help of plantings of stool and blood.

Treatment activities

Treatment depends on the cause of bleeding. First, you should, of course, stop the active bleeding, then you must prevent repeated bleeding, fighting the cause.

In order to stop the active bleeding in the alimentary canal, various endoscopic techniques are used in the first place. It is advisable that if a source of bleeding is found during gastrointestinal or colonoscopy, the cause of bleeding can also be eliminated by one of the following methods:

  • Bleeding can be stopped, for example, with a hemoclip – the type of clamp that clips the affected area.
  • There are also injection techniques, where epinephrine solution compressing the vessels is injected into the needle to bleeding site or so-called fibrin glue can be injected.
  • It is possible to use a laser that cauterizes the bleeding site.
  • The source of bleeding can be excised microsurgically.
  • In the case of varicose nodules in the esophagus and hemorrhoids, rubber ligation is often used.

When the bleeding is stopped, treatment begins, aimed at eliminating the cause of the disease:

  • With peptic ulcer, an attempt is made to reduce the production of gastric acid with the help of certain medications (proton pump inhibitors, PPI), and diet therapy can be performed. In the case of colonization of Helicobacter pylori, a combination of different antibiotics is used.
  • The cause of varicose nodules in the esophagus is high pressure in the portal vein system, and therefore try to reduce it with medication (beta blockers, spironolactone).
  • Chronic inflammatory bowel diseases require special treatment, with the use of anti-inflammatory drugs – glucocorticoids.
  • Diverticulitis is treated with antibiotics. If this is no longer possible, the affected area of the intestine is removed.
  • Polyps of the intestine are also usually removed.
  • In malignant diseases, surgical intervention, chemotherapy and radiotherapy are considered.


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