Collecting biomaterial from a baby is always a lottery for parents, especially when the laboratory is open only in the morning. It often happens that the child went to the toilet in the evening, but the tests need to be carried out early in the morning, and the acute question of preserving the sample arises.
The question of how long a baby’s stool can be stored for analysis in the refrigerator for coprogram is one of the most common in pediatric practice. The accuracy of the diagnosis and making the correct diagnosis directly depend on the correct adherence to time and temperature intervals.
In this article we will analyze the acceptable time frames, the effect of temperature on the composition of the stool and critical errors that can lead to false research results.
Why the time of collection of biomaterial is critically important
The freshness of the sample plays a key role, so how feces are an active biological environment in which the vital processes of bacteria continue even after defecation. Microbiological composition feces begin to change almost immediately after they leave the child’s body, which can distort the picture of dysbacteriosis or the presence of pathogenic microorganisms.
When long-term exposure to heat or even cold beyond the permissible time, opportunistic bacteria, which were present in minimal quantities at the time of defecation, can multiply in the sample. This will lead to the doctor receiving data about inflammation or infection where there actually is none.
In addition, the enzymatic activity in the sample does not stop instantly. Enzymescontained in the stool continue to break down nutrients, changing acidity (pH) and chemical composition, which is especially important to consider when carrying out coprogram.
Optimal temperature conditions for storage
The main factor slowing down biochemical processes in biomaterial is low temperature. However, the concept of “refrigerator” remains abstract for many parents, because in different zones of the refrigerator compartment the temperature can vary significantly.
The ideal place to place a container with feces is middle shelf a refrigerator, where the temperature usually ranges from +4 to +8 degrees Celsius. You should not place the jar on the door, as the temperature constantly fluctuates due to the opening and closing of the door, which creates unfavorable conditions for the safety of the sample.
You should also avoid placing the container near the back wall of the refrigerator, where there is a risk of the contents freezing. Freezing It is unacceptable in any case if you plan to study living flora or cellular composition.
⚠️ Attention: If your refrigerator does not have an accurate thermometer, avoid storing biomaterial for longer than 6-8 hours, since the actual temperature may be higher than that stated by the manufacturer.
How long can you store feces in the refrigerator
The answer to the question of how long you can store baby feces for analysis in the refrigerator depends on the type of study, but there are general recommendations from pediatricians and laboratory technicians. For most standard tests, including coprogram, the maximum period is from 6 to 8 hours.
Some modern preservatives and sealed containers allow you to increase this period to 10-12 hours, but this is the exception rather than the rule. Gold standard the delivery of the material to the laboratory remains within 2 hours after defecation, if this is not possible - within 6-8 hours provided they are stored in the cold.
If more than 12 hours have passed, the biomaterial is considered unsuitable for testing for dysbacteriosis and is often not suitable for coprograms, since changes in the structure become irreversible. In this case, the analysis will have to be retaken.
The table below shows the dependence of the quality of the analysis on storage time:
| Storage time | Temperature | Sample condition | Suitability |
|---|---|---|---|
| 0-2 hours | Room / Cold | Ideal | 100% suitable |
| 2-6 hours | Cold (+4...+8°C) | Good | Suitable |
| 6-10 hours | Cold (+4...+8°C) | Satisfactory | Acceptable (risk of errors) |
| More than 12 hours | Cold | Changed | Not suitable |
Rules for collecting stool in newborns and infants
Collecting biomaterial from a baby who is not yet sitting or going to the potty requires special skill and sterility. It is important to prepare everything you need in advance so as not to waste time searching for the right moment.
You will need a special one sterile container with a spoon, which can be bought at any pharmacy. The use of homemade jars for food (mayonnaise, baby food) is extremely undesirable, since microparticles of fat or detergent may remain on their walls, affecting the result.
☑️ Preparation for stool collection
The collection process is as follows:
- 👶 The child should be washed with warm water without using soap or antibacterial agents, so as not to wash off the epithelium and bacteria from the skin.
- 🧼 Dry the perineum with a clean towel or disposable napkin.
- 🩲 Put on a clean diaper or place the baby on a diaper that has been previously ironed with an iron.
- 💩 After defecation, carefully collect the feces with a spoon from the container from different places (top, bottom, edges), avoiding urine.
⚠️ Attention: If a child wears a diaper with an absorbent gel layer, you cannot collect feces from the surface of the diaper - the gel will absorb the liquid and distort the results. Use only a surface or special colostomy bags.
The influence of the type of feeding on the properties of stool
The consistency and composition of stool directly depend on what the child eats. Breast milk and artificial formulas give different reactions, and this must be taken into account when assessing the possibility of storage.
A baby's stool breastfeeding usually more liquid, yellow in color and has a sour smell. It contains more water and fewer formed particles, which makes the fermentation processes in it more active. Such a sample requires especially strict adherence to the temperature regime.
Children's feces are artificial feeding more dense, darker and have a sharper odor. The dense consistency can create the illusion of safety, but the biochemical processes inside the lumps also continue, requiring cooling.
Features of collecting liquid stool
If the stool is very liquid, it cannot be collected from an oilcloth or diaper, since the liquid some will be absorbed. Use special polyethylene urine collectors for children that are glued around the anus, or carefully place a spoon under the stream during bowel movements.
Frequent errors during storage and transportation
Even knowing the theoretical basics, parents often make practical mistakes that nullify all efforts. One of the most common is transporting it in a warm bag without refrigerant in the winter or, conversely, leaving the container in the sun in the summer on the way to the laboratory.
Another mistake is collecting material the night before “just in case.” If you are not sure that you will have time to take the test in the morning, it is better not to risk it and collect fresh material, even if you have to call a laboratory assistant at home or go to the laboratory later.
It is also a mistake to transfer feces from one container to another. Contact with air and using non-sterile containers introduces foreign microflora, which the laboratory assistant can mistake for pathogenic.
Frequently asked questions (FAQ)
Is it possible to collect stool in the evening if the test must be taken in the morning?
Yes, this is permissible, but only if stored in the refrigerator at a temperature of +4...+8°C. The time between collection and delivery should not exceed 8-10 hours. In the morning, be sure to check whether the color or smell of the sample has changed.
What to do if a child poops in a diaper with gel filler?
You cannot collect such feces. The gel absorbs the liquid fraction, leaving only dense lumps, which disrupts the ratio of elements. You need to try to catch the moment of defecation by laying out a clean diaper or using a sterile jar, placing it under the butt.
Does taking antibiotics affect the result of coprogram?
Yes, antibiotics significantly change the composition of the microflora and can suppress the growth of bacteria. Typically, a test for dysbacteriosis is taken no earlier than 10-14 days after the end of a course of antibiotic therapy, unless the doctor prescribes otherwise.
Do you need to bring a full container to the laboratory?
No, for most tests a volume the size of a walnut (about 5-10 grams) is sufficient. However, the container must be filled and tightly closed to prevent air from entering and drying out the sample.