Hi. Thanks for your query. Noted the history of suffering from constipation, bloating and belching since last 6+ months and doing night shifts since 3 years - an Upper GI Endoscopy showed antral gastritis, consulted 3 Doctors but no effective treatment. Also have lack of appetite, pain in lower and upper abdomen. I would advise you hte following in such a situation: Take a long course of a PPI like Omeprazole. You also need to take antacid, particularly whenever you are on empty stomach. Motility regulator like Domperidone. Small frequent meals of soft and bland diet. 8 hours of sound sleep in day time as you have night shifts and I hope you have to continue with this body-clock braking system No anxiety and/or stress is the key. If these measures fail, further investigations and treatment may be needed under the guidance of a Gastroenterologist.