intense pain under rib cage which goes away after drinking water suggest you are suffering from acidity or gastric ulcer. the water or food dilutes the acid in stomach and you feel relief in pain.Do not let the stomach empty. take small amount of food frequently . Tab. omeprazole on empty stomach will also be beneficial. if these remedy does not give relief within 5-7 days then kindly visit to your physician for further workup of gastric ulcer. Hope this helps. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing you good health.