1. OBJECTIVE
In this experiment, you will perform a macroscopic stool examination, in which fresh stool samples are analyzed to assess consistency and color changes, and identify the presence of parasites, parasitic structures, and/or fat.

At the end of this experiment, you should be able to:

define what are the necessary biosafety measures for the macroscopic analysis of feces;

correctly identify the type of stool sample to be used, as well as the material for collection and analysis;

recognize the importance of macroscopic analysis of feces in parasitology;

correctly identify and relate the Bristol scale to the analysis of stool consistency, defining its importance;

Between others.

2. WHERE TO USE THESE CONCEPTS?
Most intestinal parasites are diagnosed through stool examination, which demonstrates the importance of this type of examination. Stool analysis can provide a series of information from the identification of the presence of adult worms or various parasitic structures, indicating possible infection.

Consistency and color can also indicate changes in the intestinal tract, such as bleeding (in the case of red coloring). Therefore, it is possible to notice that the macroscopic analysis of the feces can provide information that allows correlating the parasites and the characteristics of the samples to the patient's symptomatology. Therefore, it is essential to guide the clinical diagnosis and allows the adequate direction of the treatment, when necessary.


3. THE EXPERIMENT
In this experiment, samples of fresh feces carefully collected in universal collectors will be used, preferably at a time close to the practice, which will need to be duly identified. Two stages of analysis will be carried out, the first being the consistency analysis and the second the color analysis and the macroscopic search for helminths. The two steps will be carried out from the same sample, which must be handled carefully to avoid contamination of the sample itself and of the person carrying out the practice, considering the current biosafety standards.

For consistency analysis, the Bistrol scale will be used, and for color analysis and macroscopic research of helminths, a visual search for helminths and/or structures will be performed, in addition to viewing the color and the presence of mucus and fat . The analysis of the results can provide information about clinical diagnosis, allowing to relate theory and practice in a contextualized way.


4. SECURITY
Carrying out this practice requires the use of personal protective equipment (PPE), in this case: gloves, long-sleeved lab coat, goggles and a mask. This equipment avoids direct contact between the handler and the sample, thus avoiding contamination. Also, according to biosafety standards, the use of thick long pants (jeans or equivalent), closed shoes with full coverage of the back of the feet and hair tied back is required, in addition to not allowing food and drinks to enter the environment from the laboratory.

The bench where the experiment will be carried out must be cleaned before and after the procedure, and it is also important to organize the necessary materials. Cleaning can be done with 1 or 2% sodium hypochlorite. Finally, gloves, toothpicks and bottles of feces must be discarded in the appropriate place for infectious waste, and glassware and other materials must be soaked in a 1 or 2% sodium hypochlorite solution, to be washed later.

5. SCENARIO
The practice will be carried out on the laboratory bench, where a wooden stick will be available for each student, the printed Bistrol scale, paper towels, pens for identifying the bottle and a container with sodium hypochlorite solution for disposal of the material used.