Blood in stool - causes, symptoms, diagnosis

A common cause of blood in the stool is intestinal bleeding.

Intestinal bleeding

Intestinal bleeding accounts for 20% of all acute, 50% of chronic and most hidden, including the most difficult for topical diagnosis, gastrointestinal bleeding.

The cause of profuse bleeding is

• duodenal ulcers - 35-40%,
• stomach ulcers - 15-20%,
• erosive-hemorrhagic gastritis - 15-20%.

Intestinal bleeding is the most difficult to diagnose, with the exception of hemorrhoids. Bleeding from the small intestine is especially difficult to identify.

Causes

The source of bleeding can be diseases of the small and large intestines, in which the integrity of the mucous membrane and other membranes of the intestinal wall is disrupted.

According to H. Hoshino, which he cited based on colonoscopy performed in 292 patients with intestinal bleeding, the most common causes were:

• ischemic colitis - 20.2%,
• hemorrhoids - 13%,
• nonspecific colitis - 8.9%,
• ulcerative colitis - 6.9%,
• colitis after antibacterial therapy - 5.5%,
• polyp - 5.5%,
• cancer - 4.8%,
• diverticulosis - 3.4%
• and other diseases of the colon (angiodysplasia, nonspecific rectal ulcer, infectious colitis, Crohn's disease, radiation colitis, tuberculosis).

Bleeding can occur with cirrhosis of the liver with portal hypertension syndrome, with tumor diseases of the biliary tract and pancreas. In these cases, blood is released along with bile or pancreatic juice.

Some blood diseases and kidney failure can also be complicated by intestinal bleeding.

What can the appearance of stool indicate?

As blood moves through the gastrointestinal tract, it acquires a dark color and gradually turns black. In case of gastric bleeding, the black color is due to the effect of hydrochloric acid on the blood.

Tarry stools appear due to the breakdown of hemoglobin by intestinal microbial flora. Blood transformations depend on the location of bleeding and the speed of its transit through the intestines.

Dark stools are more likely than bright or dark red stools to indicate bleeding from the upper gastrointestinal tract, lower small intestine, or ascending colon. Dark-colored stool may occur when there is bleeding from the lower parts of the colon if there is an obstacle to the movement of the contents below the source of bleeding.

Red blood mixed with or on the surface of the stool is a classic sign of bleeding from the distal colon.

If the source of bleeding is in the ascending colon, the stool may resemble melena but will not be shiny or sticky.

After massive bleeding, a positive reaction to blood in the stool lasts 7-10 days, sometimes up to 3 weeks. However, in some cases, the reaction to blood may become negative even 4-5 days after bleeding.

Melena can be simulated by iron and bismuth salts, charcoal, licorice root and beets. The use of the latter causes a dark red coloration of the stool. Differential diagnosis, if necessary, is helped by testing stool for blood.

The blood pigment in stool is often greatly altered. In this case, its presence is detected only through chemical reactions.

However, when assessing the results of these reactions, it is necessary to take into account that blood could enter the gastrointestinal tract

• together with saliva (for bleeding gums),
• for diseases of the nasopharynx and lungs accompanied by bleeding.

To avoid such distortion of the results, the patient is recommended not to brush his teeth 3-5 days before the test; it is necessary to exclude diseases of the nasopharynx and lungs.

On the other hand, stool is not a homogeneous mass and the part taken for analysis may not contain blood pigments.

To diagnose bleeding from the upper gastrointestinal tract should be used

• esophagogastroduodenoscopy or
• intestinoscopy (this study can be performed at the patient’s bedside and allows not only to determine the source of bleeding, but can also be used for quick therapeutic intervention).

For bleeding from the lower gastrointestinal tract, colonoscopy .

Bleeding from the small intestine is especially difficult to diagnose, and the difficulties increase as the source of bleeding moves away from the duodenal bulb.

In complex cases, it is detected using radionuclide diagnostics.

Symptoms

The clinical picture consists of the symptoms of the underlying disease and signs of blood loss.

From a practical point of view, there are

• profuse,
• light and
• hidden bleeding.

Profuse gastrointestinal bleeding has three degrees of severity:

I degree - signs of anemia are not clearly expressed, tachycardia does not exceed 100 heartbeats per minute, a decrease in blood pressure is not lower than 100-90 mm Hg. Art., hemoglobin content not lower than 83 g/l, erythrocytes - more than 3.0x10¹²/l;

II degree - pronounced signs of acute anemia (pulse rate 110 or more beats per minute, blood pressure - about 80 mm Hg, decrease in hemoglobin within 80-66 g/l;

III degree - a picture of collapse develops.

Patients with even minor blood loss are subject to hospitalization for a detailed examination.

Light and especially hidden intestinal bleeding occurs without clinical symptoms of anemia and is recognized during examination of the patient in connection with laboratory-identified iron deficiency anemia and the detection of blood in the stool.

Diagnostics

Since it is difficult to detect the source of bleeding, anemnetic data are first collected and laboratory testing is carried out.

Upper gastrointestinal bleeding usually involves vomiting and melena, although either vomiting or melena may occur.

Bloody vomiting occurs when the source of bleeding is located above the Treitz ligament. However, sometimes the cause of vomiting is a pathological process in the proximal or even distal part of the small intestine.

Information is very important

• about previous bleeding,
• alcohol abuse,
• liver diseases,
• systemic blood diseases,
• bleeding disorders,
• taking medications that cause bleeding (for example, anti-inflammatory drugs or glucocorticosteroids).

During examination, you should always exclude bleeding from the nose or oropharynx, pay attention to the presence of characteristic signs observed in liver diseases (redness of the palms, spider veins, dilation of the collateral veins of the abdominal cavity, enlarged liver, fluid in the abdominal cavity).

A proctological examination is mandatory to exclude tumors, hemorrhoids, and detect blood in the stool.

Treatment

All patients with massive bleeding are subject to urgent hospitalization in the intensive care unit. Transportation should be carried out lying on your side. In the department, the patient must be provided with complete rest, cooling of the anterior abdominal wall and fasting for 1 day.

Therapy consists of the following activities:

• intensive care for ongoing massive bleeding - examination by a surgeon, endoscopy;
• rapid restoration of circulating blood volume - intravenous administration of saline solutions and blood components;
• transfusion therapy - in case of ongoing massive bleeding, red blood cell and blood transfusions are continued;
• drug therapy - drugs are prescribed depending on the nature of the bleeding; for vascular pathology, calcium chloride and calcium gluconate are indicated; if there is a bleeding disorder, fibrinogen is prescribed;
• therapeutic endoscopy - injection treatment, mono- and bipolar coagulation, thermocoagulation; endoscopic electrocoagulation and other methods of therapeutic endoscopy make it possible to avoid surgical intervention in a significant proportion of cases.