Every time I just eat a full meal, I will have a stomachache and want to go to the toilet for some k

It is enteritis, it is recommended to take ofloxacin, and the diarrhea is stopped immediately.

After eating a full meal, the gastrointestinal activity will be active, and at the same time, when the stool accumulates too much, there will be a feeling of defecation, which should be normal, as long as it is not light pain or watery diarrhea. If the pain is light, it may be a gastrointestinal problem, and you have to go to the hospital for a check-up in order to confirm the diagnosis.

Abnormal, is not eating too much food that irritates the stomach (garlic, chili pepper, etc.).

This is not a problem of eating, it is a problem of your mentality, control your mentality, don't be nervous or excited, it will not be good for you to take the exam. It's good to face it calmly.

I wish you health and happiness.