Feces consist of water, digested and undigested food residues, bacteria, desquamated epithelium. The main part of the feces is occupied by detritus from food particles, destroyed cells of the intestinal epithelium and bacteria. The most diverse composition of excrement in children under one year old. It may include undigested muscle fibers, fatty acids, fat, starch grains. Changes in feces indicate violations of the digestive system. Fecal analysis is performed to identify or confirm the pathologies of these organs, it also allows you to evaluate the effectiveness of treatment.
When an analysis is ordered
Fecal analysis is prescribed when examining patients with diseases of the digestive tract. It reveals:
- disorders of stomach functions: synthesis of hydrochloric acid and enzymes;
- violations of the enzymatic functions of the pancreas, intestines;
- violations of various liver functions;
- malabsorption in the small intestine;
- inflammation in the digestive tract;
- malignant neoplasms of the rectum;
- defeat by helminths and protozoa.
How to take a stool test
Pee into the toilet before sampling. Feces are collected from a vessel or a pot. The container is pre-treated with a disinfectant solution, washed with running water and rinsed with boiling water. From different parts of the feces, the sample is taken using a special spoon-spatula, which is included in the disposable container. The sample should not occupy more than a third of the volume of the container. Do not touch the spoon, the inside of the lid and the container.
Feces are collected after spontaneous defecation. Not allowed:
- use of enemas, laxatives, suppositories;
- use of coloring preparations - iron, barium, bismuth.
Some studies require a special diet.
The laboratory conducts macroscopic, chemical and microscopic analysis of the biomaterial.
Macroscopic study
The doctor evaluates the amount of feces and the shape (according to the patient), consistency, color, smell.
| Macroscopic evaluation of feces | |
| Quantity | |
| 100-200g | Norma |
| Decrease | Predominance of proteins in the diet, constipation, spastic colitis |
| Increase | Affection of the pancreas, insufficient digestion in the colon (dyspepsia, inflammation), colitis with diarrhea, acceleratedevacuation |
| Consistency | |
| Dense, decorated | Norm, digestive disorders in the stomach |
| Mazevidny | Impaired secretion of the pancreatic gland - acute pancreatitis, pancreatic necrosis, cystic fibrosis |
| Thin, watery |
Insufficiency of digestion in the small intestine - enteritis, lack of bile, accelerated evacuation Colonic lesion - ulcerative colitis, putrefactive colitis (decreased water absorption) |
| Pushy | Fermentative dyspepsia, colitis, chronic enterocolitis, accelerated excretion of feces from the colon |
| Foamy | Fermentative colitis, dysbacteriosis |
| Crinkly decorated colorless | Lack of bile - cholelithiasis |
| Large lumps, hard stool once every few days | Constipation |
| Small, rounded fragments - "sheep" feces | Spastic colitis |
| Ribbon-shaped, pencil-shaped | Hemorrhoids, rectal sphincter spasm, anal fissure, rectal swelling |
| Color | |
| Brown | Norma |
| Black | Bleeding from stomach, small intestine |
| Dark brown | Digestion problems in the stomach, putrefactive dyspepsia, colitis with constipation, increased secretory function of the large intestine |
| Light brown | Accelerated passage of chymein the colon |
| Redish | Ulcerations (fresh blood) |
| Yellow | Insufficiency of digestion in the small intestine, fermentative dyspepsia, accelerated progress through the intestines |
| Grey, pale yellow | Pancreatic insufficiency |
| White | Bilestone blockage |
| Smell | |
| Missing | Constipation |
| Rotten | Digestion problems in the stomach, putrefactive dyspepsia, ulcerative colitis |
| Smelly (rancid butter) | Impaired secretion of pancreatic lipase, lack of bile (fat is decomposed by bacteria) |
| Sour | Fermentation processes in the large intestine (volatile acids are formed), failures in the absorption of fatty acids in the small intestine - enteritis, accelerated passage of split food |
| Fecal reaction | |
| Neutral or slightly alkaline (pH 6.8-7.6) | Norma |
| Alkaline (pH 8.0-8.5) | Insufficiency of the stomach (lack of hydrochloric acid) or small intestine (rotting proteins leads to the formation of alkaline substances such as ammonia) |
| Highly alkaline (pH above 8.5) | Putrid dyspepsia with colitis |
| Sour (pH 5.5-6.7) | Pathologies of fatty acid absorption |
| Highly acidic (pH below 5.5) | Fermentative dyspepsia (formation of carbon dioxide and volatile acids) |
Chemical study of feces
Chemical research can be carried out by the express method using test strips. Chemical analysis of feces includes the detection of protein, occult blood, bilirubin, stercobilin and the establishment of pH.
There is no protein in the feces of a he althy person. The detection of this element indicates inflammation, bleeding, or the presence of undigested food protein in the stool. A positive protein test indicates a lesion:
- stomach (cancer, ulcer, gastritis);
- small intestine (duodenitis, enteritis, ulcer, cancer, celiac disease);
- colon (colitis, polyps, cancer, high secretory function, dysbacteriosis);
- colon (proctitis, cancer, hemorrhoids, fissure).
Blood in stool
Preparation for analysis has its own specifics:
- One week before the fecal occult blood test, you need to stop the use of iron, vitamin C, non-steroidal anti-inflammatory drugs (Paracetamol, Ibuprofen, Aspirin);
- eliminate foods high in iron for three days - liver, meat, fish, and green plants;
- eliminate stool-coloring foods for two days - beets, blueberries, pomegranate;
- exclude the ingress of blood from the oral cavity - tooth extraction, nosebleeds; for bleeding gums, replace brushing with rinsing.
Blood in the stool can be detected by visualexamination, examination under a microscope, or a chemical reaction. To detect occult blood, a qualitative reaction is carried out for hemoglobin, which is contained only in it. Normally, there is no hemoglobin in the stool.
A stool test to detect this indicator is prescribed to detect bleeding in the digestive tract.
Detection of visible or occult blood indicates pathologies:
- hemorrhoids in the rectum, dilated veins of the esophagus, stomach, intestines;
- gastric or intestinal ulcers, acute or chronic inflammation of the digestive organs;
- polyps in the intestines;
- malignant tumors in the digestive tract;
- dilated veins in liver cirrhosis;
- intestinal tuberculosis;
- helminths that damage the intestinal wall;
- hemorrhoidal diathesis.
Detection of blood is a serious symptom requiring medical attention.
Stercobilin, bilirubin
Stercobilin is formed from bile bilirubin in the large intestine during the vital activity of microflora. The substance gives the feces a brown color. In the case of a complete blockage of the bile duct, it is absent in the feces, and the feces become colorless.
Bilirubin is found in the feces of breastfed children up to the third month of life, while the intestinal microflora is only populated. By the 9th month, the biocenosis of the large intestine is formed and completely utilizes bilirubin. From this age, the presence of this component in the feces indicates a pathology: dysbacteriosis or the rapid passage of food throughintestines.
The detection of both stercobilin and bilirubin in the analysis of feces shows that pathogenic microbes have colonized the large intestine and replaced the normal flora.
Microscopic examination of feces
Drops of the prepared stool emulsion are stained with different reagents and examined under a microscope. This is how food remains are found. Their composition and quantity depend on the work of the digestive organs and diet, so before taking the test, the doctor may ask the patient to adhere to an average diet without a clear predominance of meat or vegetables, especially without sufficient heat treatment.
Leukocytes are absent in the feces of adults and children, they can be found in a minimal amount only in infants. The detection of leukocytes indicates the presence of an inflammatory process in the colon or the decay of the tumor.
At standard microscopic examination, the detection of eggs of helminths and protozoa is likely. They are absent in the feces of he althy people, a small amount of yeast fungi is allowed.
Study of feces for helminths and protozoa
If there are signs of a person being affected by helminths or protozoa, a special study of feces is prescribed to identify them, which is somewhat more difficult. Some types of microorganisms can only be found in warm stools - no later than 20 minutes after a bowel movement.
With a single study, traces of helminths are rarely found. Therefore, the analysis of feces for worm eggsrepeat two more times with a one- and two-week interval. If helminthiasis is established and treatment is prescribed, a control analysis is carried out one month after the start of therapy.
Pinworm eggs are not detected in feces. To detect them, they take a scraping from the skin around the anus.
Study of feces for dysbacteriosis
Microbiological examination of feces allows you to establish violations of the composition of the intestinal flora, as well as to identify infectious agents.
Feces for dysbacteriosis should not be taken after taking antibiotics or chemotherapy drugs. Careful toileting of the anus is essential before sampling. Collect feces in special sterile test tubes.
The human intestine is populated by microflora in childhood. Each person has a different qualitative and quantitative set of microorganisms. In total, about 500 different types of bacteria are found in the large intestine. A small number of species are permanent for the host, they prevail in number, they perform numerous functions. The usual microflora necessarily includes bifidobacteria, eubacteria, lactobacilli. Temporary bacteria are always present in the intestines - they are few, but their composition is diverse, pathogenic ones can be found among them.
The use of antibiotics and malnutrition, under certain conditions, upset the balance in the composition of the microflora, which is fraught with the appearance of pathologies. Clinical manifestations of dysbacteriosis are blurred and nonspecific. Therefore, the diagnosis can only be established by the results of a fecal analysis fordysbacteriosis. This is a serious pathology that requires treatment. The imbalance of microorganisms is especially dangerous for children.
Deciphering the analysis of feces does not replace going to the doctor. Choose a qualified specialist, do not self-medicate.
