Cats with diarrhea after changing their food will usually recover on their own within 2 to 3 days. Cats with fragile stomachs may need about two weeks to recover. If the diarrhea lasts longer, they need to go to the hospital to check whether they have gastroenteritis or other other diseases. Cats' gastrointestinal tracts are relatively sensitive. When changing food, you should pay attention to the ratio of old and new cat food, and do it step by step so that the cat can slowly adapt. You can also use probiotics to help cats regulate their gastrointestinal tract.