The digestion of food after oral intake is mainly divided into two parts: gastric digestion and intestinal digestion. The time for gastric digestion is mainly related to the structure of the food. For simple carbohydrates and vegetables, the digestion time is 2-4 hours. For fats, oils and proteins, the digestion time is 6-8 hours. In case of mixed foods, it is 5-6 hours. The intestinal digestion time is highly fluctuating and varies significantly from person to person. It takes 3-4 days for some patients to digest and absorb all the food, and some patients can completely digest and absorb the ingested food within one day. However, as long as the patient does not have any obvious uncomfortable reaction after eating, and at the same time, the body does not have symptoms such as malnutrition, it is generally a physiological adjustment and does not require intentional drug treatment.