Feces consist of water, digested and undigested food debris, bacteria, desquamated epithelium. The main part of feces is detritus from food particles, destroyed intestinal epithelial cells and bacteria. The most diverse composition of excrement in children up to a year. It may include undigested muscle fibers, fatty acids, fat, and starch grains. Changes in feces indicate violations of the digestive system. An analysis of feces is carried out to identify or confirm pathologies of these organs, it also allows you to evaluate the effectiveness of treatment.
When an analysis is prescribed
Fecal analysis is prescribed for examination of patients with diseases of the digestive tract. It allows you to identify:
- disorders of the functions of the stomach: 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 tumors of the rectum;
- defeat by helminths and protozoa.
How to take a stool test
Before sampling, you need to urinate in the toilet. Feces are collected from a vessel or pot. Previously, the container is 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 spatula spoon included in the kit of the disposable container. The sample should not occupy more than a third of the container. Do not touch the spoon, the inner surface of the lid and container should not be.
Feces are collected after spontaneous bowel movements. Not allowed:
- the use of enemas, laxatives, suppositories;
- the use of coloring preparations - iron, barium, bismuth.
With some studies, it is necessary to prescribe a special diet.
The laboratory conducts macroscopic, chemical and microscopic analysis of biomaterial.
Macroscopic examination
The doctor estimates the amount of feces and the form (according to the patient), the consistency, color, smell.
| Macroscopic evaluation of feces |
| number |
| 100-200 g | Norm |
| Decrease | Protein predominance in the diet, constipation, spastic colitis |
| Increase | Damage to the pancreas, insufficient digestion in the colon (dyspepsia, inflammation), colitis with diarrhea, accelerated evacuation |
| Consistency |
| Tight, decorated | Normal, digestive upsets in the stomach |
| Peloid | Pancreatic secretion disorder - acute pancreatitis, gland necrosis, cystic fibrosis |
| Liquid, watery | Insufficiency of digestion in the small intestine - enteritis, lack of bile, accelerated evacuation The defeat of the colon - colitis with symptoms, putrefactive colitis (decreased absorption of water) |
| Mushy | Fermentative dyspepsia, colitis, chronic enterocolitis, accelerated excretion of feces from the colon |
| Foamy | Fermentative colitis, dysbiosis |
| Tiny decorated colorless | Lack of bile - cholelithiasis |
| Large lumps, dense feces once every few days | Constipation |
| Small, rounded fragments - "sheep" feces | Spastic colitis |
| Ribbon-shaped, pencil-shaped | Hemorrhoidal nodes, rectal sphincter spasm, anus fissure, rectal tumor |
| Color |
| Brown | Norm |
| The black | Bleeding from the stomach, small intestine |
| Dark brown | Digestive disorders in the stomach, putrefactive dyspepsia, colitis with constipation, increased secretory function of the large intestine |
| Light brown | Accelerated passage of chyme through the colon |
| Reddish | Ulceration (fresh blood) |
| Yellow | Insufficiency of digestion in the small intestine, fermentative dyspepsia, accelerated bowel movement |
| Gray, pale yellow | Pancreatic insufficiency |
| White | Stoned bile duct obstruction |
| Smell |
| Is absent | Constipation |
| Putrefactive | Digestive disorders in the stomach, putrefactive dyspepsia, ulcerative colitis |
| Offensive (rancid oil) | Impaired pancreatic secretion of lipase, lack of bile (fat is decomposed by bacteria) |
| Sour | Fermentation processes in the colon (volatile acids are formed), failure of the absorption of fatty acids in the small intestine - enteritis, accelerated passage of split foods |
| Fecal reaction |
| Neutral or slightly alkaline (pH 6.8-7.6) | Norm |
| Alkaline (pH 8.0-8.5) | Lack of stomach function (lack of hydrochloric acid) or small intestine (protein decay leads to the formation of alkaline substances, such as ammonia) |
| Highly alkaline (pH above 8.5) | Putrid dyspepsia with colitis |
| Acidic (pH 5.5-6.7) | Fatty Acid Absorption Pathologies |
| Highly acidic (pH below 5.5) | Fermentative dyspepsia (carbon dioxide and volatile acids are formed) |
Chemical study of feces
Chemical research can be carried out by 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 stool of a healthy person. The detection of this element indicates inflammation, bleeding or the presence of undigested food protein in the feces. A positive test for protein indicates damage:
- stomach (cancer, ulcer, gastritis);
- small intestine (duodenitis, enteritis, ulcer, cancer, celiac disease);
- colon (colitis, polyps, cancer, high secretory function, dysbiosis);
- rectum (proctitis, cancer, hemorrhoids, fissure).
Blood in the feces
Preparation for analysis has its own specifics:
- a week before stool analysis for occult blood, the use of iron, vitamin C, non-steroidal anti-inflammatory drugs (Paracetamol, Ibuprofen, Aspirin) should be discontinued;
- for three days, exclude foods with a high iron content - liver, meat, fish, as well as green plants;
- in two days to exclude foods that stain feces - beets, blueberries, pomegranates;
- exclude blood from the oral cavity - tooth extraction, nosebleeds; with bleeding gums, replace brushing with rinses.
Blood in the stool can be detected by visual inspection, examination under a microscope or chemical reaction. To detect hidden blood, a qualitative reaction is carried out on hemoglobin, which is contained only in it. Normally, hemoglobin in feces is absent.
An analysis of feces to identify this indicator is prescribed to detect bleeding in the digestive tract.
Detection of visible or latent blood indicates pathologies:
- hemorrhoidal nodes in the rectum, expansion of the veins of the esophagus, stomach, intestines;
- stomach or intestinal ulcers, acute or chronic inflammation of the digestive system;
- polyps in the intestine;
- malignant tumors in the digestive tract;
- venous expansion with cirrhosis;
- intestinal tuberculosis;
- helminths that damage the intestinal wall;
- hemorrhoidal diathesis.
Blood detection is a serious symptom that requires medical attention.
Sterkobilin, bilirubin
Sterkobilin is formed from bilirubin of bile in the large intestine during the life of microflora. The substance gives the feces a brown color. In the case of complete blockage of the bile duct, it is absent in the feces, and the feces become colorless.
Bilirubin is found in the feces of breast-fed children until the third month of life, while the intestinal microflora is only populated. By the 9th month, a biocenosis of the large intestine is formed and completely utilizes bilirubin. From this age, the presence of this component in feces indicates a pathology: dysbiosis or the rapid passage of food through the intestines.
The detection of both stercobilin and bilirubin in the analysis of feces shows that the large intestine was colonized by pathogenic microbes 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. So find food residues. Their composition and quantity depend on the work of the digestive organs and diet, therefore, before taking the analysis, the doctor may ask the patient to adhere to an average diet without the obvious predominance of meat or vegetables, especially without sufficient heat treatment.
White blood cells are absent in the feces of adults and children, can be found in a minimum amount only in infants. The detection of leukocytes indicates the presence of an inflammatory process in the colon or the decay of the tumor.
With standard microscopic examination, the detection of eggs of worms and protozoa is likely. In the feces of healthy people, they are absent, a small amount of yeast fungi is allowed.
The study of feces for helminths and protozoa
If there are signs of human damage with helminths or protozoa, a special study of feces is prescribed to identify them, which is somewhat more complicated. Some types of microorganisms can be found only in warm feces - no later than 20 minutes after a bowel movement.
With a single study, traces of helminths are rarely detected. Therefore, the analysis of feces for worm eggs is repeated two more times with one and two week intervals. 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, take a scraping from the skin around the anus.
Study of feces for dysbiosis
Microbiological examination of feces allows you to establish violations of the composition of the intestinal flora, as well as identify pathogens.
Feces for dysbiosis cannot be taken after taking antibiotics or chemotherapeutic drugs. A thorough toilet of the anus is required before sampling. Type feces in special sterile tubes.
The human intestine is colonized by microflora in childhood. Each person has a 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 constant for the host, in number they prevail, it is they who perform numerous functions. The usual microflora necessarily includes bifidobacteria, eubacteria, lactobacilli. Temporary bacteria are always present in the intestines - there are few of them, but their composition is diverse, pathogenic ones can be found among them.
Acceptance of antibiotics and improper nutrition under certain conditions upset the balance in the microflora, which is fraught with the appearance of pathologies. The clinical manifestations of dysbiosis are blurred and nonspecific. Therefore, a diagnosis can be established only by the results of an analysis of feces for dysbiosis. This is a serious pathology requiring treatment. Imbalance in the balance of microorganisms for children is especially dangerous.
Deciphering the feces analysis does not replace a visit to a doctor. Choose a qualified specialist, do not self-medicate.