There are many kinds of diarrhea, the most common one is eating bad things and catching a cold. Diarrhea drugs can solve the problem. If it's serious, it's up to the doctor to tell you what kind.
Such as gastrointestinal cold, enteritis, gastritis, cold, eating bad things, indigestion, spleen and stomach problems will cause diarrhea.
By the way, people will lose weight if their spleen and stomach are not good. You can recuperate if you take Chinese medicine. Enteritis is fast, and western medicine is fast.
Gastrointestinal colds should not be blown by cold air for a long time, and try to avoid eating cold drinks. In short, touch less cold things.
Gastroenteritis eats less irritating foods such as seafood and peppers, and eats more foods that are beneficial to gastrointestinal mucosa.
Disharmony between the spleen and stomach, deficiency and the like are hard to say, because there are many kinds, so we should find really good Chinese medicine practitioners. You can't take medicine casually, it will be more serious if you eat it wrong.