Hi thanks for contacting HCM... If you have eaten outside food then it can be food poisoning or gastroenteritis.... Here pain in stomach could be by ulcer or chronic gastritis.... If you have stomachache still now follow below instruction.... Take omeprazole for 2 week... Ofloxacine tablet for 5 days ... More water .... Green leafy veg more.... Outside non veg food avoided.... High fatty diet restricted as they delay gastric emptying.... Bluberries rich in vitamin c and fiber....having antioxidant property also so good to take.... Cooked oatmeal help in soothing stomach.. Fruits taken more... Avoid smoking , alcohol and excess tea .. Let me know you chronic constipation also can lead gastric pain... So treat it with fiber supplement if needed. Take care.... If still symptom continue USG done.. Dr.Parth