Diarrhea can occur when eating greasy food is related to the following factors: 1. greasy diet will increase the burden on the digestive tract, thus leading to diarrhea in patients. 2. patients may have some primary diseases in the past, such as biliary tract diseases, pancreatic diseases, and weak gastrointestinal tract function, if they eat greasy diet at this time, they are unable to secrete the corresponding digestive enzymes because of the corresponding diseases, and are also prone to diarrhea. 3. gastrointestinal tract function is in If the gastrointestinal tract is in a state of agitation, greasy diet is a stimulating diet that can lead to intestinal nerve spasms, which can also lead to abdominal pain and even diarrhea. Therefore, in addition to avoiding greasy diets, it is also necessary to go to the hospital to rule out the presence of corresponding biliary and pancreatic diseases so as not to miss the diagnosis and treatment of the corresponding diseases.