Conducting a stool occult blood test, preparing for the analysis of what you can eat and what needs to be excluded

Nutrition in preparation for diagnosis - diet before donating stool for occult blood

During the diet, before testing feces for occult blood, you must avoid consuming apples, white beans, cucumbers, spinach, cauliflower, horseradish, meat and fish products. Tomatoes, bell peppers and green vegetables are also prohibited.

Patients are allowed to consume potatoes, cereals, and dairy products. You need to eat in small portions without overeating. It is important to avoid frying; Instead, food is boiled, stewed or baked .

Sources

• Pelitari S., Gautham A., Mistry P., Mohan S., Brookes M., McKaig B., Shah A., Jewes S., Fieldhouse G., Veitch A., Murugananthan A. Impact on healthcare resources of switch from fecal occult blood test to fecal immunochemical test within the English Bowel Cancer Screening Program: a single-center study. // Gastrointest Endosc - 2021 - Vol - NNULL - p.; PMID:33727015
• Kim YJ., Shim JI., Park E., Kang M., Kang S., Lee J., Tchoe HJ., Kong KA., Kim DH., Kim BC., Choi KS., Moon CM. Adherence to follow-up examination after positive fecal occult blood test results affects colorectal cancer mortality: A Korea population-based cohort study. // Dig Liver Dis - 2021 - Vol - NNULL - p.; PMID:33676856
• Lu J., Xu B., Xu Y., Wu Y., Xie J., Wang J., Lin J., Chen Q., Cao L., Zheng C., Huang C., Li P. A Novel Insight Into Fecal Occult Blood Test for the Management of Gastric Cancer: Complication, Survival, and Chemotherapy Benefit After R0 Resection. // Front Oncol - 2021 - Vol10 - NNULL - p.526746; PMID:33643891
• Bujang NN., Lee YJ., Mohd-Zain SA., Aris JH., Md-Yusoff FA., Suli Z., Abu-Hassan MR., Bhoo-Pathy N. Factors Associated With Colorectal Cancer Screening Via Immunochemical Fecal Occult Blood Test in an Average-Risk Population From a Multiethnic, Middle-Income Setting. // JCO Glob Oncol - 2021 - Vol7 - NNULL - p.333-341; PMID:33625866
• Azulay R., Valinsky L., Hershkowitz F., Elran E., Lederman N., Kariv R., Braunstein B., Heymann A. Barriers to completing colonoscopy after a positive fecal occult blood test. // Isr J Health Policy Res - 2021 - Vol10 - N1 - p.11; PMID:33573698
• Chang JY., Moon CM., Shim KN., Cheung DY., Lee HS., Lim YJ., Jeon SR., Park SJ., Kim KO., Song HJ., Jang HJ., Kim JH. Positive Fecal Occult Blood Test is a Predictive Factor for Gastrointestinal Bleeding after Capsule Endoscopy in Patients with Unexplained Iron Deficiency Anemia: A Korean Multicenter CAPENTRY Study. // Clin Endosc - 2021 - Vol53 - N6 - p.719-726; PMID:33153246
• Zamorano-Leon JJ., López-de-Andres A., Álvarez-González A., Maestre-Miquel C., Astasio-Arbiza P., López-Farré A., de-Miguel-Diez J., Jiménez-García R ., Albaladejo-Vicente R. Trends and Predictors for the Uptake of Colon Cancer Screening Using the Fecal Occult Blood Test in Spain from 2011 to 2021. // Int J Environ Res Public Health - 2021 - Vol17 - N17 - p.; PMID:32867168
• Wang HY., Lin TW., Chiu SY., Lin WY., Huang SB., Hsieh JC., Chen HC., Lu JJ., Wu MH. Novel Toilet Paper-Based Point-Of-Care Test for the Rapid Detection of Fecal Occult Blood: Instrument Validation Study. // J Med Internet Res - 2021 - Vol22 - N8 - p.e20261; PMID:32763879
• Yang C., Wu W., Yang Y., Yang X., Sun J., Zhang W., Liu K., Ying H., Jiang S., Yu X., Shi Y., Zhou Y., Zhu S ., Xu Y., Ding Y., Xie L., Cai B., Xin X., Chen P., Zhao R., Wu Y. Multitarget stool DNA test compared with fecal occult blood test for colorectal cancer screening. // Oncol Lett - 2021 - Vol20 - N2 - p.1193-1200; PMID:32724359
• Ishida N., Miyazu T., Matsuura T., Takano R., Tamura S., Kagami T., Tani S., Yamade M., Hamaya Y., Iwaizumi M., Osawa S., Furuta T., Sugimoto K .Effect of ulcerative colitis duration on the usefulness of immunochemical fecal occult blood test result as a disease activity biomarker. // Int J Colorectal Dis - 2021 - Vol35 - N9 - p.1729-1739; PMID:32472230

Basic principles of the diet before donating stool for occult blood

Basic principles of the diet before donating stool for occult blood:

It is necessary to exclude meat, fish, eggs, legumes and green vegetables from the diet.
• Portions should be small so that a person does not feel heavy in the stomach.
• During the diet, you should not take antibiotics or laxatives.
• It is allowed to consume dairy products, mashed potatoes, and oatmeal decoction.
• Instead of coffee and black tea, you should drink water, dried fruit compotes, and fresh juices.

Pros and cons - diet before donating stool for occult blood

The advantages of dieting before donating stool for occult blood include:

High efficiency. Beneficial effect on the digestive organs. No need to starve. Help in obtaining reliable analysis results.

However, each diet has not only pros, but also cons: the patient is allowed to consume very few foods. They can get boring after a few days.

Most familiar dishes are excluded from the menu. The diet is not easy for all patients, but it is effective, so such restrictions are understandable .

This technique has no contraindications, but in the presence of chronic diseases, the doctor can adjust the diet, add or exclude certain foods. It is necessary to consult a doctor.

Research methods: pros and cons

Currently, four main methods are used to determine occult blood in feces:

• Gregersen reaction (benzidine test);
• Weber reaction (guaiac test);
• Immunochemical analysis of stool;
• Fluorescence test.

Let's understand the essence of these methods, their advantages and disadvantages. Looking ahead, we note that in Russia the benzidine test and immunochemical analysis are most often used, but are they the most accurate?

Gregersen reaction (benzidine test)

The benzidine test is a simple and quick laboratory test that detects blood not only in the stool, but also, for example, in the patient’s urine, vomit and any other biological fluid. This is possible due to the oxidation of benzidine (paradiaminodiphenyl) with hydrogen or barium peroxide in the presence of hemoglobin. The benzidine test has several variations, the most commonly used of which was proposed by the doctor M. Gregersen, which is why it bears his name.

The essence of the method is as follows: take 0.025 g of benzidine, add 0.1 g of barium peroxide and 5 ml of a 50% acetic acid solution to it, shake everything until completely dissolved, apply a few drops of the composition to a glass slide, on which the feces being tested are spread in a thin layer, and observe the reaction. If there is occult blood, a bright blue-green color appears. There is an alternative option - prepare a saturated solution of benzidine in acetic acid and mix it with a 3% solution of hydrogen peroxide in equal parts. The result will look approximately the same, and the cost of the study will change little.

Pros:

• Very high sensitivity – 1:100,000;
• The speed of obtaining results is almost instantaneous;
• Availability in any laboratory;
• Low price.

Minuses:

• The need for careful preparation for taking a stool occult blood test using the Gregersen method, since the benzidine test gives a positive reaction to animal hemoglobin from food.

Weber reaction (guaiac test)

In addition to the two mentioned, this diagnostic method has several more names: Van Deen or Almen-Van Deen test, hemoccult test. Interestingly, the reaction using guaiac resin is the first method in world medical practice for detecting hidden blood in human feces and other biological fluids. Dr. Van Deen proposed it in 1864 and it is still actively used in many countries.

The essence of the guaiac test is as follows: take 3-5 g of the feces being tested, dissolve it in acetic acid, which releases an ethereal extract, add hydrogen peroxide and tincture of guaiac resin to it, and then observe the color change of the reagents in a test tube. If the composition turns blue, it means that the result of the test for occult blood in the stool is positive. The test is repeated a total of six times: two samples from biomaterials, taken sequentially over three days, are studied.

Pros:

• Efficiency.
• Affordable price.

Minuses:

• Low sensitivity - the reaction will be positive only in case of blood loss of 30 ml or more, colorectal cancer is detected in a third of cases, benign intestinal tumors - only in 15% of cases;
• Strict dietary requirements before fecal occult blood testing - the guaiac test is sensitive not only to the heme peroxidase of human hemoglobin, but also to the peroxidases of other hemes contained in food.

Immunochemical analysis of stool

This analysis is otherwise called an immunological or immunochromatographic test. The technique is based on the reaction that occurs when specific antibodies interact with hemoglobin in human blood. Errors are excluded because the antibodies do not react to animal hemoglobin or iron contained in some plant foods. Immunochemical analysis of feces for occult blood appeared in the arsenal of doctors relatively recently and has already firmly established itself there.

The essence of the technique is as follows: a sample of the feces being tested is applied to a test strip or placed in the window of a tablet with reagents - monoclonal antibodies. If human hemoglobin is present in the biomaterial, it binds to antibodies, and a bright pink or purple stripe appears in the control area. The second band appears in any case - it is an indicator of the good quality of the device. Taking a stool occult blood test using this method is very similar to taking a pregnancy test - everything is very simple, quick and understandable.

At the pharmacy you can purchase “ImmunoCHROM-GEM-Express” or any other similar device for self-diagnosis of hidden gastrointestinal bleeding at home, however, to obtain a reliable result, it is recommended to carry out the analysis at least three times with intervals of several days.

Pros:

• Speed ​​and convenience;
• No need for preliminary preparation and diet;
• High accuracy - detects early stages of colorectal cancer in 97% of cases.

Minuses:

• Relatively high cost;
• Not available in every laboratory;
• The objectivity of the results of a fecal occult blood test is only in the case of bleeding in the lower parts of the digestive tract. Aggressive enzymes acting on hemoglobin in the stomach and small intestine render it in a state unsuitable for reacting with monoclonal antibodies.

Fluorescence test

To complete the picture, it should be mentioned that occult blood can be detected in feces during a chemical reaction using destructive reagents. Nitrogen-containing pigments, porphyrins, contained in hemoglobin molecules and released when they die, have an ultra-high light absorption coefficient - about 10 to the 6th power. Their bright fluorescent glow is recorded by a laboratory technician if there is hidden blood in the stool sample being examined. However, in Russia this diagnostic method is not very popular, especially in comparison with the benzidine test.

Pros:

• Efficiency;
• Affordable price;
• Relatively high accuracy - about 80%.

Minuses:

• The need to follow a diet, since porphyrins are present in any hemoglobin, including in animals.

Sample diet menu before donating stool for occult blood

In order not to make mistakes in nutrition, before donating stool for occult blood, you need to familiarize yourself with the diet menu compiled by specialists:

List of allowed foods during the diet before donating stool for occult blood

During the diet, before donating feces for occult blood, you can consume:

Dairy products - milk, kefir, low-fat cottage cheese. Porridge - rice, buckwheat. Vegetables - potatoes, beets, carrots. Fruits - peaches, persimmons. Drinks - jelly, compote, berry juice.

It is allowed to add a little butter to dishes. During lunch or dinner, you can eat a slice of bread. The main thing is not to eat buns and flour products, they are prohibited. You can add a little sugar to tea, but you should not eat the sweets themselves .

What should not be consumed during the diet before testing for occult blood?

Diet patients should avoid the following before donating stool for occult blood:

Vegetables and fruits are green. Meat and fish. Seafood. Nuts. Legumes. Dairy products - fermented baked milk, sour cream, yogurt. Drinks - alcohol, sweet carbonated drinks, coffee.

It is necessary to give up not only the food mentioned above, but also spices, flavorings, and sweeteners. Smoked meats, semi-finished products, and salted foods are also prohibited.

For the results to be reliable, you need to give up cereals such as barley, millet, wheat . They may negatively affect the diagnosis.

Duration of the diet before donating stool for occult blood

The duration of the diet before donating feces for occult blood is 3-5 days, no more. Typically, patients need three days to prepare for the test. The diet is stopped after the test.

To prevent the body from experiencing stress, switch to normal nutrition gradually. You cannot immediately switch to familiar dishes and products .

They are added in small quantities to the menu while continuing to consume healthy foods. This will allow you to switch to your usual diet without negative effects on the body.

Dairy version of the diet - diet before donating stool for occult blood

The diet before donating feces for occult blood is often used due to its high efficiency. Its main principles include:

During the day, a person consumes mainly dairy products, and fruits and vegetables in small quantities. It is allowed to consume cottage cheese, milk, kefir. Porridge is cooked with milk, and casseroles are made from cottage cheese. Adding sugar and sweet syrups to dairy products is prohibited.

The program lasts 3-5 days, the doctor can tell you exactly how long this diet will last. In addition to milk, you are allowed to drink water, compotes, jelly and berry decoctions .

Before donating stool for occult blood, a diet is necessary: ​​it helps prepare for the test, cleanses the body, and has a beneficial effect on the human condition.

Knowing the principles of such nutrition, a person will do an excellent job of preparing the body for analysis, and the results will be reliable.

About the FOBT Study

FOBT is a laboratory test used to test stool for occult blood. Occult blood is blood that you cannot see just by looking at the stool. There are many reasons for blood in your stool. Your healthcare provider will explain to you why you are having this test.

To complete the FOBT, you will collect stool samples for 3 consecutive days. This increases the likelihood of detecting blood, since bleeding may not happen every day. If you have no bowel movements on any of these 3 days, talk to your healthcare provider. He will discuss with you the possibility of collecting 3 samples over a longer period of time.

to come back to the beginning

What does a stool occult blood test reveal?

During an annual medical examination, people over 40 years of age are recommended to take a stool test for occult blood.
The analysis reveals gastrointestinal pathologies in the early stages, which makes it possible to use it as a screening method. Any inflammation, polyp or tumor of the intestine is accompanied by bleeding, but the amount of blood is so small that it cannot be determined visually. However, this amount is sufficient to determine blood contamination using a laboratory method.

There are two methods for determining occult blood in stool:

benzidine, guaiac tests - shows the admixture of any hemoglobin in the stool. Therefore, this method gives a number of errors in the absence of preparation in the form of a special diet three days before the test. The immunochemical method is the most accurate, as it shows the presence of human hemoglobin, and not what comes with food. The method does not require special preparation. The disadvantage of the immunochemical method is the long readiness period, about 14 days.

Types of research

To determine the presence of occult blood in stool, specialists use several methods. One of them is called the Gregersen method. It involves adding benzoin or guaiac to the sample. This substance, in the presence of hydrogen peroxide, produces a blue coloration of the iron transport molecule. This way, doctors will be able to find even a small amount of hemoglobin in the stool.

This method has a number of negative aspects. Since blood cells of human or animal origin may enter the stool, the accuracy of the result cannot be completely relied upon. This technology allows you to determine blood loss of more than 15 ml per day. However, normally this figure is 1 ml or less. Therefore, to confirm the data obtained using the Gregersen method, specialists use other methods.

Doctors obtain more reliable readings from immunochemical analysis. This is the name for a technique based on the specific effect of antigens on antibodies characteristic of a particular patient. The disadvantage of this method is the time required to obtain the result - it takes about two weeks.

Immunochromatographic examination of stool is considered more convenient and simpler. To carry it out, monoclonal antibodies are used, which in prepared form are applied to the test strip. And if the indicators are in order, the person will see one strip. If the amount of blood in the stool is higher than normal, there will be two stripes. This is similar to a pregnancy test. A special feature of this method is that there is no need to prepare for the procedure for a long time. Based on it, we can conclude about the presence of colon cancer with an accuracy of up to 97%. However, it does not provide information about pathological abnormalities in the small intestine.

Another method used to study stool in some clinics is fluorescent analysis. For this purpose, the assessment of the submitted material is carried out after it has been specially processed and exposed to light. In this way, porphyrins formed as a result of the breakdown of hemoglobin cells are detected. Approximately one day before the test, you should not consume animal products. By complying with this condition, it will be possible to reduce the risk of obtaining a false result.

When choosing one of the analysis methods, you should pay attention to its focus. No less important indicators will be its prevalence and price.

When is a referral for analysis issued?

In addition to screening the age group over forty years, the doctor writes a referral for this test in the following cases:

• for abdominal pain
• nausea
• frequent heartburn
• with an iron taste in the mouth
• if you have no appetite
• if you experience sudden weight loss
• constant loose and mushy stools
• if you suspect an ulcer or gastritis.

The analysis reveals the slightest damage to the walls of the intestine. If an admixture of blood higher than normal is detected in the stool, the test is repeated and, if the result is confirmed, the patient is sent to see a proctologist or gastroenterologist.

Who needs examination

According to scientists, the length of the intestines in adults is approximately 8 meters. And it is impossible to completely control the digestive system. It is often possible to identify diseases in it by examining impurities. However, such a test is done when a patient visits a doctor with complaints of:

• episodic or constant abdominal pain;
• regular occurrence of nausea, vomiting, diarrhea, heartburn;
• chronic type disorders during defecation;
• significant weight loss for an unknown reason.

Such an analysis is done to persons who are diagnosed with an ulcer, gastritis or other disorder associated with a violation of the integrity of the walls in the intestines or stomach. Then the meaning of the procedure is to confirm the diagnosis. Suspicions of Lynch syndrome, Crohn's disease, or helminth infection also give doctors reason to order this test.

Preparation for analysis.

To avoid distortion of the results, three days before the test you should:

• exclude from the diet meat and fish, apples, beans, as well as green and red vegetables (beets, tomatoes, zucchini, spinach, etc.)
• brush your teeth carefully (it is better not to brush on the eve of the test), especially if your gums are weak and bleeding
• if there was an x-ray examination, then three days should pass after it
• If a woman is menstruating, the test should be postponed
• feces should be obtained through natural bowel movements, without an enema
• there should be no urine or water in it.
• Do not use laxatives, including herbs.
• stop taking medications a week before (check with your doctor)
• stool must be delivered to the laboratory no later than three hours after collection.

False positive result: what is it and what is the reason?

A false positive result may indicate a reaction to iron of a different origin.

What to do: perform the enzyme immunoassay test “Colon View Hb and Hb/Hp”. It reacts only to human hemoglobin and the hemoglobin/hapten complex.

A false positive result can result from:

• Gingivitis is an inflammation of the gums, accompanied by increased bleeding during eating and especially brushing teeth. Ingestion of blood causes a positive test result.
• Errors in diet. A false positive result can be obtained due to a nonspecific reaction to iron-containing substances of food origin. That is why it is necessary to strictly exclude the consumption of meat, fish, apples, spinach, herbs, cauliflower, tomatoes and some other vegetables a few days before the analysis.
• Taking certain medications. These include iron-containing (anti-anemic) medications, bismuth-based drugs, vitamin complexes, acetylsalicylic acid (aspirin and blood thinners based on it), ascorbic acid (vitamin C). Of course, it is necessary to inform the laboratory staff about their use, and stop taking them only in agreement with the attending physician.
• Iatrogenic (arising as a result of the actions of a doctor) damage to the walls of the digestive organs. Carrying out FGDS, sigmoidoscopy, X-ray contrast diagnostic techniques, enemas may be accompanied by microtraumas of the mucous membrane, which will lead to the appearance of hidden blood in the feces.
• The presence of bleeding hemorrhoidal veins or anal fissure . And in women, a positive result can be obtained during menstruation, when blood released from the genital tract is mixed with the stool.

What does a stool occult blood test reveal?

A positive result may indicate suspicion of the following types of disease:

• Hemorrhoids and anal fissure;
• benign tumors (polyp)
• Bowel cancer
• Intestinal inflammation
• Helminthiasis;
• Crohn's disease
• Diverticulosis
• Nonspecific ulcerative colitis
• Ulcer

Fecal occult blood testing is an important method for diagnosing gastrointestinal diseases. Sometimes only with its help it is possible to detect pathology in the intestines.

It is recommended to take a stool occult blood test once a year.

Rules for sampling

The consistency of the result with reality is also influenced by the correctness of the collection. To do this, you need to follow a number of rules. Feces are given in a special container purchased at a pharmacy. When collecting it, you must follow the following algorithm:

• before emptying, make sure that there is no liquid in the samples (for example, lay oilcloth material in the toilet);
• after defecation, take a sample for research in the amount of three teaspoons;
• take the test to a medical facility no later than 3 hours later.

When prescribing an analysis for a baby, it is allowed to collect material from a diaper or diaper.

Recommendations for patients on preparing for laboratory tests

1. It is recommended to donate blood for laboratory tests in the morning, on an empty stomach, after an 8-12 hour fast. You can drink water. If it is not possible to visit the laboratory in the morning, you can donate blood during the day. 2. You must refrain from physical activity or drinking alcohol for 24 hours before taking blood. 3. Blood is taken for analysis before starting to take medications (for example, antibacterial and chemotherapy) or no earlier than 10-14 days after their discontinuation). If you are taking medications, be sure to notify your doctor. 4. Blood should be donated before X-ray, endoscopic or physiotherapeutic procedures. 5. Immediately before taking blood for testing, you must: • do not eat food after 20.00; • in the morning after getting up, refrain from smoking; • when donating blood, it is necessary to exclude factors that influence the research results: physical stress (running, climbing stairs), emotional arousal. Therefore, immediately before the procedure you should rest for 10-15 minutes and calm down.

It is very important that you strictly follow these recommendations, as only in this case the results will be correct!

To obtain accurate diagnostic data in the results of laboratory analysis, it is necessary to follow several rules before submitting the analysis:

General blood analysis

1. Blood is donated in the morning on an empty stomach between 8 and 10 am. Blood sampling is allowed during the daytime and evening hours, 3 hours after the last meal. 2. On the eve of the study: • 1-2 days before the study, exclude fatty, fried foods, alcohol and smoking from the diet; • exclude physical activity, avoid stressful situations; • if possible, eliminate physical and emotional stress; • donate blood before starting physiotherapeutic procedures, as well as x-ray and ultrasound examinations, since exposure to low-frequency or high-frequency radiation can change the hematological parameters of the blood (the concentration of leukocytes and hemoglobin decreases). Also, you should not donate blood after massage and other medical procedures (for example, endoscopic examinations); • blood for research must be donated before starting to take medications or no earlier than 10 - 14 days after their discontinuation. If you are taking medications, be sure to notify your doctor.

Blood chemistry

1. Blood is taken for testing after 12 hours of fasting and abstaining from drinking alcohol and smoking, preferably in the morning (between 8 and 10 a.m.), with minimal physical activity. 2. Donate blood before starting physiotherapeutic procedures, as well as x-ray and ultrasound examinations, since exposure to low-frequency or high-frequency radiation can change the hematological parameters of the blood (the concentration of leukocytes and hemoglobin decreases). Also, you should not donate blood after massage or other medical procedures (for example, endoscopic examinations). 3. Blood for research must be donated before starting to take medications or no earlier than 10 - 14 days after their discontinuation. If you are taking medications, be sure to notify your doctor. 4. For a number of studies, blood should be donated strictly at a certain time of day. So, blood tests for some hormones (TSH and parathyroid hormone), as well as for iron, are given only before 10 a.m. 5. During hormonal studies in women of reproductive age, the results are influenced by physiological factors associated with the stage of the menstrual cycle. Therefore, when preparing for examination for the hormones FSH, LH, prolacti, estriol, estradiol, progesterone, the phase of the cycle should be indicated.

General urine analysis

1. On the eve of taking a urine test, it is not recommended to eat vegetables and fruits that can change the color of urine (beets, carrots, etc.), and not to take diuretics. 2. It is advisable that the previous urination was no later than 2 am. 3. Before collecting urine, you need to thoroughly clean the external genitalia. Women are not recommended to take a urine test during menstruation. 4. Collect approximately 50 ml. morning urine into a urine collection container. Screw the lid on the container and deliver the urine to the laboratory. It is allowed to store urine in the refrigerator (at t + 4 + 8 ° C), but no more than 1.5 hours.

Urinalysis according to Nechiporenko

1. On the eve of the test, it is not recommended to eat vegetables and fruits that can change the color of urine (beets, carrots, etc.), and not to take diuretics. 2. Before collecting urine, you need to thoroughly clean the external genitalia. Women are not recommended to take a urine test during menstruation. 3. Collect morning urine in the following order: a small initial portion of urine is poured into the toilet at the count: 1.2. Then, the average portion of urine is collected in a container, at least 10 ml, and complete urination into the toilet. 4. Screw the lid on the container and deliver the urine to the laboratory. It is allowed to store urine in the refrigerator (at t + 4 + 8 ° C), but no more than 1.5 hours.

Urine analysis according to Zimnitsky

1. On the eve of the test, it is not recommended to eat vegetables and fruits that can change the color of urine (beets, carrots, etc.), and not to take diuretics. 2. Urine is collected for 24 hours with normal eating and drinking regimen (1.5-2 liters per day). The volume of liquid consumed during the period of urine collection (including the volume of first courses) is recorded, indicating the time of liquid intake. 3. At 6 a.m., empty your bladder into the toilet. Then, sequentially collect all the urine into 8 bottles, changing the bottle every 3 hours: a) 1 portion - from 6-00 to 9-00 in the morning; b) 2 servings - from 9-00 to 12-00; c) 3rd portion - from 12-00 to 15-00; d) 4 servings - from 15-00 to 18-00; e) 5th portion - from 18-00 to 21-00; f) 6th portion - from 21-00 to 24-00; g) 7th portion - from 24-00 to 3-00; h) 8th portion - from 3-00 to 6-00 At night, you need to set an alarm clock to maintain the urination regime. If there is no urine within 3 hours, leave the bottle empty. 4. Deliver the entire collected amount of urine in 8 containers, closed with lids, to the laboratory.

1. Feces are collected after spontaneous defecation in specially designed containers (disposable plastic containers with a sealed lid and a spatula for collecting a stool sample); 2. You cannot send material for research after an enema, taking medications that affect intestinal motility, after taking castor or vaseline oil, after administering suppositories, drugs that affect the color of stool (iron, bismuth, barium sulfate), bring feces in diapers to the CDL . The stool should not contain urine. 3. The container with feces is delivered to the laboratory immediately after defecation or no later than 10-12 hours after defecation, subject to storage in the refrigerator at a temperature of +3-5 °C.

Examination of feces for occult blood

I. Examination of feces for occult blood (Gregersen reaction):

II Examination of feces for occult blood (immunochemical method):

1. This method does not require restrictions on food intake. 2. Stool immunochemical testing should not be performed within fourteen days after medical procedures or examinations of the gastrointestinal tract during which a medical instrument was used. 3. The stool should be natural, without the use of laxatives and enemas.

Ultrasound of the abdominal organs 1. The most appropriate time for the study is in the morning on an empty stomach. If the study is to be performed in the afternoon, a light breakfast is allowed in the morning and the interval between meals and ultrasound is at least 6 hours. 2. 2-3 days before the examination, it is recommended to exclude from the diet foods that increase gas formation in the intestines (raw vegetables rich in plant fiber, whole milk, brown bread, legumes, carbonated drinks, as well as high-calorie confectionery products - pastries, cakes). 3. If you are prone to increased gas formation, it is recommended to take enterosorbents (for example, activated carbon or espumizan, 2 tablets 3 times a day) 2–3 days before the test.

Ultrasound of the thyroid gland, ultrasound of the scrotum, ultrasound of the kidneys. These studies do not require special preparation.

Ultrasound of the bladder The study is carried out with a full bladder, so you need to drink 1 hour before the procedure the following amount of non-carbonated liquid (depending on age): 1 year - 100 ml; 3 years - 150ml; 5 years -170-200ml; 7 years - 300ml; 10 years 3-300-350ml; 13 years and older 500 ml.

X-ray examination of the stomach and duodenum (gastroscopy)

X-ray examination of the kidneys (excretory intravenous urography)

1. Eliminate from the diet foods that contribute to gas formation (vegetables, fruits, sweets, milk, brown bread). 2. You can take activated charcoal as prescribed by your doctor. 3. Limit fluid intake to 1 leaf from the second half of the day before the study. 4. Cleansing enemas in the morning and evening.

Decoding the results

After conducting research, you can get several options for results. If 1-2 ml of blood loss is detected in a man or woman, this is considered normal. In this case, the test will give a negative result. And there is no need to worry about problems in the intestines.

In some cases, the doctor speaks of a weakly positive or false positive result. This often means that the patient has not prepared well enough for the procedure. In some cases, this reveals polyps or other formations in the intestines, the bleeding of which is periodic. In this case, the test is performed by colonoscopy.

If significant losses of hemoglobin are detected in the stool, the result will be interpreted as positive. In this case, the specific cause of bleeding will also be identified by colonoscopy. Depending on the diagnosis, the patient will be referred to the appropriate specialist.

The quality of the analysis performed and interpreted depends on the class of the laboratory performing the work. And in order not to make a mistake in your choice, you should be aware of the main medical institutions providing their services in Moscow. You can find out online the cost of the analysis, the method of conducting it, and quickly make an appointment with a specialist.

Esophagogastroduodenoscopy (EGDS)

Esophagogastroduodenoscopy is an endoscopic examination in which the upper parts of the gastrointestinal tract are examined: the esophagus, stomach and duodenum. Endoscopy requires special preparation, which you need to know in advance: 1. Two days before the test, chocolate, nuts, seeds, and spicy foods should be excluded from the diet. 2. The last meal before the study should be no later than 21:00 the previous day. Dinner should not contain food that is difficult to digest. It is necessary to exclude foods rich in fiber, heavy salads dressed with mayonnaise, whole grain bread, meat, fish, cheeses, legumes, and pearl barley. 3. The study is carried out on an empty stomach! 4. If you suffer from chronic diseases that require constant use of medications, the medications cannot be discontinued. They should be taken 3 hours before the test with a small amount of water. 5. Before the study, you must inform your doctor about your existing allergies to medications, if you have one, and what medications you are taking. What to take with you to a gastroscopy? • results of past gastroscopic examinations, ultrasound; • towel or small sheet.

Sample collection

Figure 1. Hemoccult slide

Prepare everything you need

You will need the following:

• Hemoccult® slide;
• applicator stick;
• clean dry container;
• trash bin.

Instructions

1. Prepare everything you need. Place all items in the bathroom so that you can easily reach them.
   Remove the Hemoccult slide from the paper envelope. Set the envelope aside.
2. Do not place the Hemoccult slide and applicator wand on the edge of a sink, bathtub or toilet. They cannot be wet.
3. Keep Hemoccult slides at room temperature away from heat and light.
4. Check that the card contains your name, date of birth and medical record number. If this information is not listed on the card, write it down.
5. Fold down the large front flap of the Hemoccult slide. You may notice a light blue discoloration of the paper in the squares above fields A and B. This will not affect the test results.
6. Sit on the toilet as usual to have a bowel movement (big pee). Use a clean, dry container to catch the stool before it touches the toilet water.
7. Using the end of the applicator stick, take a stool sample. Place a thin smear of stool inside square A on the Hemoccult slide (see Figure 1).
8. Using a stick, take a second sample from another part of the stool. Apply a thin smear of stool inside square B.
9. Throw the stick in the trash.
10. Close the flap of the Hemoccult slide and place it back into the paper envelope. Do not put it in waterproof packaging such as a plastic bag. Store it at room temperature away from light, children and pets.
11. Dispose of the contents of the stool container into the toilet. Flush the toilet.
12. Wash your hands. Wet your hands with warm water and scrub them with soap for at least 20 seconds. Rinse your hands.

Repeat these steps to collect samples on days 2 and 3. Write the date of collection next to each sample.

to come back to the beginning

Fibercolonoscopy

Fibercolonoscopy is an endoscopic examination during which the condition of the colon mucosa is visually assessed, that is, under visual control. 1. The study is carried out on an empty stomach. Taking medications is allowed. Preparation for colonoscopy: 2. In order to examine the mucous membrane of the colon, it is necessary that there is no feces in its lumen. Two days before the test, it is recommended to eat broth, boiled meat, fish, chicken, eggs, cheese, white bread, and cookies. Fruits, vegetables, herbs, cereals, legumes, mushrooms, berries, and grain bread should be excluded. 3. On the eve of the study - water-tea diet (mineral water, tea, clear juices, broths).