The common symptoms of eating a bad stomach are bloating, abdominal pain, diarrhea and so on. 1. Bloating: after eating a bad stomach, food accumulates in the gastrointestinal tract, and after fermentation, there will be an increase in gas production, so the phenomenon of bloating will occur. 2. Abdominal pain: there will be bacterial infection in the gastrointestinal tract after eating a bad stomach, and the mucous membrane of the gastrointestinal tract infected by bacteria may lead to gastrointestinal tract spasms, resulting in abdominal pain. 3. diarrhea: due to inflammation infiltration infection, intestinal mucosal permeability changes, a large amount of water into the intestinal tract after the emergence of diarrhea, and nutrients can not be absorbed, the food through the excretion of the way out, will aggravate the symptoms of diarrhea. Eating bad stomach in addition to the above symptoms, but also can be manifested as fever, nausea and vomiting, loss of appetite, weakness and other symptoms, such as eating bad stomach diarrhea, abdominal pain and other discomforts, it is recommended to seek medical attention, during the period of time need to eat a light diet, and under the guidance of the doctor to actively treat, to avoid delaying the condition.