A stool examination is a procedure to examine a stool or stool sample. Stool examination aims to detect diseases or disorders of the digestive system.
Stool examination begins with taking a sample of the patient's stool. Next, the stool sample will be taken to the laboratory for examination. Stool samples will be assessed for consistency, color, and odor, and seen whether they contain mucus or not.
Stool examination also aims to check the presence of blood, sugar, fat, infection-causing microorganisms, bile, and white blood cells, as well as to measure the level of acidity in stool samples.
Stool examination is divided into two types, namely:
- Occult blood test or fecal occult blood test (FOBT), to find the presence or absence of blood in the stool by using chemicals
- Stool culture, to detect the presence of bacteria that cause infections in the digestive tract
Indications for Stool Examination
The doctor will perform a stool examination on patients suspected of having the following conditions:
- Allergies or inflammation in the digestive tract, such as milk allergy in babies
- Infections, whether caused by bacteria, fungi, worms, or viruses, that attack the digestive tract
- Nutritional indigestion or malabsorption syndrome
- Bleeding in the digestive tract
In addition, stool examination is also carried out to:
- Knowing the cause of the symptoms of gastrointestinal disorders, such as nausea, vomiting, diarrhea, flatulence, abdominal pain or cramps, slimy bowel movements, and fever
- Detect cancer or precancerous polyps in the colon, by looking at the presence or absence of blood in the stool
- Identify diseases of the liver, pancreas, or digestive tract, by checking the level of enzymes in the patient's stool
Stool Check Alert
Before undergoing a stool examination, there are several things that must be known, namely:
- Stool examination should not be done during menstruation or if you are suffering from bleeding due to hemorrhoids.
- The FOBT examination is only to detect the presence of blood in the stool, but cannot determine the cause of the bleeding.
- FOBT examination is not always accurate in detecting colon cancer. Therefore, the results of the FOBT examination showing the presence of blood in the stool sample must be accompanied by a colonoscopy.
- Stool samples used for examination must not be samples that have fallen to the bottom of the toilet, exposed to urine, or exposed to toilet paper.
- It is advisable to notify the doctor if you have recently had an X-ray using barium contrast or if you have traveled abroad in the last few weeks.
- It is advisable to tell your doctor about any medications, supplements, or vitamins you are taking. The doctor may ask the patient to stop taking antacids, laxatives, antidiarrheals, non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, and antiparasitics before the examination.
Before Stool Examination
Patients who want to undergo a stool culture can eat and drink, and take medication as usual. However, in patients who plan to undergo a FOBT stool examination, the doctor will ask the patient not to consume red meat, fruit, vegetables, vitamin C supplements, and NSAIDs for 3–7 days before the examination.
Stool Examination Procedure
Stool examination begins with taking a stool sample, which can be done at home or in a hospital. The doctor or nurse will explain to the patient the correct procedure for taking a stool sample and provide an airtight plastic container to hold the stool sample.
The following are the steps you can take to take a stool sample:
- Try to urinate first before defecating, so that the stool sample to be taken is not mixed with urine.
- Put plastic wrap in the closet when you are about to defecate, so that feces do not spill or fall to the bottom of the toilet and become contaminated.
- Use a special spoon or spatula to take a stool sample about the size of a date seed, then transfer it to a container.
- Make sure the stool sample is not mixed with water or toilet paper.
- After the stool sample is collected, immediately put it in a plastic bag and make sure it is tightly closed.
- Wash your hands thoroughly with soap and water, then write your name, date of birth, and date of collection of stool samples on the container to prevent the containers from being mixed up.
Bring the container with the stool sample to the laboratory immediately, no later than 24 hours after sampling, to prevent the growth of bacteria that could affect the test results.
In some cases, the doctor will tell you if the container containing the sample can be stored in the refrigerator. However, before storing it, put the container in an airtight bag first.
Stool examination can be done more than once. For example, examination of feces to determine the presence or absence of fat, stool samples were taken for 3 consecutive days.
Meanwhile, in patients who experience symptoms of digestive tract disorders after returning from abroad, stool samples are taken for 7-10 consecutive days.
Stool sample examination
The method of examining stool depends on the type of procedure. In the FOBT procedure, a stool sample will be smeared onto a test card. After that, a chemical liquid will be dripped onto the card. If there is blood in the stool sample, the color of the test card will change after the chemical is added.
Meanwhile, in the stool culture procedure, the stool sample will be placed in a container that has been smeared with a special liquid to encourage bacterial growth. The container containing the stool sample is then stored for 2-3 days in the incubator.
After incubation, the doctor will examine the stool sample using a microscope, to see if there is abnormal bacterial growth in the stool.
After Stool Examination
Patients will generally get the results of a stool examination in 1-3 days. The characteristics of normal stools are as follows:
- Brown color, soft texture, and the overall shape is consistent
- Does not contain bacteria, viruses, fungi, parasites, mucus, pus, blood, and meat fibers
- Contains 2-7 grams of fat in 24 hours
- Contains less than 0.25 gram/dL gula sugar
- Has an acidity level of 7.0–7.5
The following is an explanation of the results of the FOBT stool examination and stool culture:
FOBT examination results
The results of the FOBT examination can be negative or positive. A negative result means that there is no blood in the patient's stool sample. Even so, that does not mean the patient does not have the risk of developing colon cancer later in life. Therefore, patients are advised to have a FOBT examination once a year.
Meanwhile, a positive result indicates the presence of blood in the patient's stool sample. However, a positive result also does not always indicate the patient has colon cancer, but can also be due to polyps, hemorrhoids, or inflammation. So to be sure, the doctor will perform additional examinations, such as a colonoscopy.
Stool culture results
The results of the stool culture examination were declared normal if no abnormal bacteria were found in the patient's stool sample. On the other hand, abnormal results indicate that there are abnormal bacteria in the patient's stool sample, which may indicate that the patient has a gastrointestinal infection.
In patients who get abnormal results, the doctor will carry out further examinations or immediately provide treatment according to the test results.
Risks of Stool Examination
Stool examination is safe to do. However, the process of taking stool samples must be carried out carefully, because stool samples may contain harmful germs.
Therefore, make sure to wash your hands with water and antibacterial soap until they are completely clean. This aims to prevent transmission if there are harmful microorganisms in the stool sample.