Hi Dear, Welcome to HCM. Understanding your concern. As per your query you have symptoms of bowel movement upon intake of food along with gastritis which can occur due to many reasons for symptoms you mention in query like gastroenteritis, food intolerance, food allergies, irritable bowel syndrome, appendicitis and giardiasis. In your case the symptoms are probably due to food intolerance. You should take small and frequent meals and avoid taking large meals at at time. For now eat light and non spicy , take antacid after every meal, drink plenty of water and take light walk after every meal. You should take oral rehydrating solution as well. I would suggest you to consult gastroenterologist for proper examination. Doctor may order ultrasound , endoscopy or stool test. Doctor may also order allergy test. Doctor may prescribe antacids along with proton pump inhibitors such as omeprazole , laxative , ornidazole or albendazole. Hope your concern has been resolved. Get Well Soon. Best Wishes, Dr. Harry Maheshwari