Stomach ache from eating hard things indicates that hard things cause irritation to the gastrointestinal tract, and it is also related to the factors such as indigestion and diseases of the gastrointestinal tract. 1. Indigestion: because of the improper diet will increase the burden on the gastrointestinal tract, it may lead to the symptom of stomach pain when eating hard things. 2. Gastrointestinal diseases: Gastritis, gastric ulcer, duodenal ulcer, cholecystitis and other diseases may cause damage to the mucous membrane of the gastrointestinal tract or abnormal secretion of digestive juices, which may lead to the symptom of stomach pain when you eat hard food. If the symptoms are persistent or recurring, it is necessary to go to the hospital for appropriate examinations to determine the cause of the problem and follow the doctor’s instructions.