Collecting biomaterial from a small child often turns into a real operation, requiring maximum composure and speed from parents. Children's feces it is necessary to deliver it to the laboratory within a strictly defined time frame so that the research results are reliable and do not require a repeat procedure. Any violation of the temperature regime or exceeding the permissible time interval can lead to a change in the chemical composition of the sample, the death of pathogenic bacteria or the active reproduction of opportunistic flora.
Many parents wonder whether it is possible to leave a container with biomaterial in the refrigerator overnight if the child went to the toilet late in the evening. The answer to this question depends on the type of test ordered by the doctor and the age of the child. In some cases, storage is acceptable for a short period of time, in others, the material is considered unusable within an hour after defecation. Understanding these nuances allows you to avoid false diagnoses and non-nervous treatment.
In this article we will analyze in detail the permissible storage periods for various types of research, the peculiarities of the temperature regime and the rules for preparing a sterile container. Compliance with the algorithm of actions guarantees that the laboratory technician will receive a high-quality sample for study, and you will receive an accurate result. Do not neglect the rules of transportation, as the health of your baby depends on it.
General requirements for the collection of biomaterial from children
The process of collecting feces from children, especially infants, has its own unique features that directly affect the possibility of storage. Sterility is the first and main condition. You cannot collect material from the surface of a diaper, from a pot (if it has not been pre-treated with boiling water) or a diaper, since the absorbent layer of the diaper instantly absorbs the liquid fraction, making the sample unsuitable for analysis.
For collection, you must use special pharmaceutical containers with a spoon or sterile jars with a wide neck. If the child does not yet know how to use the potty as intended, pediatricians recommend using sterile urine bags or placing a clean, ironed oilcloth under the butt. It is important to collect biomaterial from different places, since parasites or blood impurities may be distributed unevenly.
⚠️ Attention: It is strictly forbidden to use food containers, matchboxes or medicine jars to store biomaterial. Even after washing, microparticles of detergent or chemicals may remain on their walls, which will distort the chemical analysis.
The volume of collected material also has meaning. For most studies, an amount equal to the volume of a walnut or 5–10 grams is sufficient. Too much biomaterial in the container can lead to its rapid oxidation upon contact with air, even inside a closed container.
Storage periods depending on the type of analysis
The time during which children's feces retain their properties directly depends on the purpose of the laboratory test. Different techniques reveal different indicators, and the sensitivity of these indicators to external conditions varies greatly. Therefore, there is no universal answer to the question “how long can you store” - everything is decided by the type of test prescribed.
The most common is coprogram (general stool analysis). It allows you to assess the functioning of the digestive system, the presence of inflammation and the quality of food digestion. For this type of analysis, the biomaterial is relatively stable, but there are severe limitations. If you leave the sample at room temperature, the decay processes will begin to change the picture within an hour.
Why is time so important?
The intestinal microflora begins to change immediately after defecation. Bacteria that lived in anaerobic conditions enter an oxygen environment and begin to actively multiply or die, which distorts the real composition of the microflora.
Tests for occult blood and worm eggsare more demanding. In the first case, chemical reactions can occur quickly, and in the second, helminth larvae can be destroyed or, conversely, activated, which makes them difficult to detect under a microscope. The most “capricious” test is considered to be a test for dysbacteriosis, which requires delivery to the laboratory almost instantly.
Temperature regime: refrigerator or room temperature?
The question of where exactly to store container until the trip to the clinic is critical. Room temperature (about +20...+22°C) is favorable for the rapid development of bacteria. If you plan to take the test within 30-40 minutes after collection, storage at room temperature out of direct sunlight is allowed.
However, if longer storage is required, refrigeratorbecomes the only safe place. The optimal zone is the middle shelf, where the temperature stays within +2...+4°C. You should not place the container on the refrigerator door, as the temperature fluctuates there due to frequent opening, or at the back wall, where freezing is possible.
It is strictly forbidden to freeze biomaterial! Ice crystals destroy the cell walls of bacteria and the structure of epithelial cells, making the sample unsuitable for microscopy. After defrosting, it will no longer be possible to obtain a reliable result. Therefore, there is one rule: only cooling, but not freezing.
| Type of analysis | Storage temperature | Maximum period (refrigerator) | Maximum period (room) |
|---|---|---|---|
| Coprogram (general) | +2...+4°C | up to 8-10 hours | up to 1-2 hours |
| Egg worm | +2...+4°C | up to 6-8 hours | up to 1 hour |
| For occult blood | +2...+4°C | up to 6 hours | Not recommended |
| For dysbacteriosis | +2...+4°C | up to 2-3 hours | Not recommended |
Nuances for infants and children up to one year
In newborns and breastfed children, the stool has liquid or mushy consistency and yellowish color. This creates additional difficulties for collection and storage. The liquid fraction reacts faster with oxygen and the walls of the container. Therefore, for infants, the “collected - carried” rule works best.
If the child is on artificial feeding, his feces are more formalized, but still require quick delivery. The peculiarity of children's metabolism is that fermentation processes in the intestines continue even after defecation more actively than in adults. Enzymes that enter the feces continue to break down nutrients, changing the chemical composition of the sample.
If you do not have time to take the test in the morning (for example, the child pooped at 5 in the morning, and the laboratory opens at 8), storage in the refrigerator is acceptable. However, for infants it is better to reduce this period to a minimum - no more than 4-5 hours. Ideally, if the child went to the toilet at night, try to collect the morning feces that will appear after the first feeding.
Rules for transportation to the laboratory
Delivery of the container to a medical facility is the final and very important stage. Even if you have collected and cooled the material correctly, it can be damaged along the way. The main task is to maintain the temperature regime. During the warm season or during a long trip, it is better to place the container in a cooler bag or wrap it in refrigerant (but avoid direct contact with ice).
During transportation, avoid strong shaking and shaking. Shaking can lead to mixing of layers, if any, or mechanical destruction of delicate structures. If you are carrying the test on public transport, keep the bag with the container in your hands, and not in the trunk or on the floor, where the temperature may be lower or higher than necessary.
⚠️ Attention: Before taking the test, be sure to check with the reception of your laboratory about their internal rules. Some private clinics accept biomaterial only in the morning and may refuse a sample collected yesterday, even if stored correctly.
Do not forget to label the container correctly. The sticker must indicate the child’s name, date and exact time of collection of the material. An error in time may lead to the fact that the laboratory technician considers the sample expired and will not accept it for work.
Checklist for preparing for the analysis
To systematize the process and not miss anything, use our short algorithm of actions. This will help reduce stress and avoid mistakes that may cost you a second trip to the pharmacy and clinic.
☑️ Algorithm of actions for parents
Frequently asked questions (FAQ)
Is it possible to collect stool in the evening if the analysis is scheduled for the morning?
Yes, for general analysis (coprogram) and analysis for worm eggs, it is allowed to collect biomaterial in the evening of the previous day. In this case, the container should be stored in the refrigerator at a temperature of +2...+4°C for no more than 8–10 hours. For analysis of dysbacteriosis, evening collection is not recommended, since the composition of the microflora will change overnight.
What to do if a child pooped in a diaper?
Collecting feces from the surface of a regular diaper is impossible, since the gel will absorb the liquid. If the diaper is without gel filler (gauze or fabric), you can assemble it. As a last resort, if the feces are dense, you can carefully collect the top layer from the surface of the diaper without touching the absorbent layer, but the information content of such an analysis will be reduced.
Is it possible to freeze feces for analysis?
No, freezing feces is strictly prohibited. Ice crystals destroy the cellular structure of bacteria, protozoa and epithelial cells. After defrosting, microscopic examination will show a non-viable mass, and the result will be incorrect.
Is it necessary to wash the child before collecting feces?
Yes, hygiene procedures are required. The child should be washed with warm water and baby soap and wiped dry with a clean towel. This is necessary so that foreign impurities, urine residues or cosmetics from the skin do not get into the sample, which can distort the chemical analysis.