Diarrhea after eating in a restaurant is considered to be acute gastroenteritis (requiring rehydration, antidiarrheal, anti-infection and other treatments), dyspepsia (requiring pro-digestive and other treatments), food allergy (requiring antidiarrheal, anti-allergy and other treatments) and other problems, which need to be analyzed specifically. 1. Acute gastroenteritis: diarrhea after eating in the restaurant may be acute gastroenteritis, need to rehydration (such as intravenous supplementation of 5% to 10% glucose sodium chloride solution), antidiarrheal (such as montelukast, etc.), anti-infective (such as cefuroxime, etc.) and other symptomatic treatment. 2. Indigestion: diarrhea after eating in a restaurant may be indigestion, need to drink more water, and promote digestion (such as digestive enzymes, etc.), probiotics (such as Bacillus licheniformis) to regulate intestinal flora and other symptomatic treatment. 3. Food allergy: diarrhea after eating in a restaurant may be food allergy (such as seafood allergy, etc.), need to drink more water, and anti-diarrhea (such as montelukast, etc.), anti-allergy (such as loratadine, etc.) and other treatments. There are many reasons for diarrhea after eating in a restaurant, it is recommended to consult a doctor in time, after a clear diagnosis and timely treatment, to avoid delaying the condition.