In the afternoon, I suddenly had a stomachache and wanted to endure going to the toilet after class,

This is normal!

When you go out, who won't encounter some difficulties, and if you're not feeling well, it's even less likely to be belittled. >>>More

There is no need to take medicine, in this case, you should drink cold drinks first, and then eat hot ones. At night, the heat does not cooperate with the cold and causes pain, so it is good to pull it up.

Buy some aconite Li Zhong pills and eat it, this is a lack of middle qi and yang deficiency.

Depending on your description, consider pain-induced vascular neurogenic syncope. This is not necessarily a disease, it can be seen in people without organic diseases, and it is caused by the excitement of the vagus nerve caused by pain.

Hurry up and go to the hospital for examination, you ask here and there are no test results, so it is not good to give you a diagnosis, and it will be treated formally. Now is the season of change, and the stomach becomes prone to problems.