History noted. Its so great that you are free of major problems in this age group. Yup for the gastritis
the tablet you have mentioned is fine. Kindly take it for 15 days, before breakfast. Also take 2 and half litres of water per day. Avoid roots and fried items.Eat easily digestible diet. Please avoid oily and spicy food stuffs.Practice a relaxed walking daily for 20 minutes.For the symptoms you have mentioned , my suggestion is to do a screening upper GI scopy as well as colonoscopy
to rule out major bowel disorders.