Exams
There are two fecal occult blood tests and they are not prepared the same way
What does the fee schedule say?
Fonasa's 2026 MLE fee schedule carries two separate lines, and the method is what separates them.
| Catalogue name | Code | Which technique |
|---|---|---|
| Hemorragias ocultas (benzidine, guaiac or Weber test and similar), any method, per sample | 03-08-004 | The classic chemical version |
| Immunochemical or immunological analysis of occult blood in stool | 03-08-062 | The antibody-based version, known as the fecal immunochemical test |
What changes for you, the person bringing the sample?
How many times, and what you can eat. MedlinePlus describes the guaiac version as one that collects samples from several different bowel movements, and it asks you to avoid certain foods and medicines in the preceding days.
The same page describes the immunochemical version as a more sensitive test that needs only one sample and carries no dietary restrictions. That difference decides whether your week changes.
Which other stool tests does it get confused with?
- Serial stool parasitology. Several samples on alternate days, a container with preservative, a different bench in the lab.
- Stool culture. Looks for bacteria, needs a sterile container and comes with its own delivery window.
- Fecal calprotectin and fecal leukocytes. Different markers, different processing, different codes in the fee schedule.
All four are requested as a stool test and none accepts another's container. A sample in the wrong pot is a lost exam, and the exam order starts over.
What does the centre prepare?
The lab hands over the container, the collection instructions and the deadline for bringing the sample in. Exam preparation depends on the method that lab uses, so one centre's rules do not transfer to another.
Why does such a cheap order get lost?
Because it has no appointment. An exam with no slot generates no reminder, no confirmation and no no-show. The patient keeps the order fully intending to go, and nothing ever prompts them.
That is the widest blind spot in any centre: orders with no calendar entry appear in no attendance metric at all. The care gap exists all the same, leaving no trace in the system.
The other failure mode is the sample arriving late or in the wrong container, and that one is solved with clear instructions delivered at the right moment.
What should I do if I am holding one?
- Check whether the order says guaiac, immunochemical, FIT or simply hemorragias ocultas.
- Call the laboratory and ask which method they use and how many samples they expect.
- Collect the container before you need it. This is the step most often postponed.
- Confirm the sample reception hours, which are usually shorter than the opening hours.
- Set a concrete date to take it in, exactly as you would for any appointment.
Getting a reminder for an exam that has no booked slot sounds odd, and it is precisely what is missing. Centres running Surface already do it, and finding out whether yours is one takes a single question.