Hello, you should understand that stomach pain occur due to numerous reasons like gastritis due to untimely eating habits and having spicy oily foods, food allergies can cause this symptoms if you are susceptible to have allergic reaction by having a particular food substances, food poisoning due to unhygienic food preparation, constipation mainly due to decreased fibre content in the diet you consum, lactose intolerance due to enzyme deficiency so avoidance of diary products itself acts as a prevention,gastroesophageal reflux disease, ulcers, indigestion one of this might be the cause for your problem. So get a opinion of physician for further management