Suggest Treatment For Severe Abdominal Pain

Hi, I ve been feeling small aches on my left side of the abdomen... undeneath the rib cage, on the left side of the navel, an on my side on top of my hip. It s not very painful. I did experienced bloating and gas. No nausea or vomiting. When, I touch the area underneath my rib cage and left to my navel... I feel like small lumps and it hurts a bit when I touch it. I did went to the doctor (yesterday) and he said that it s just gastritis and prescribed me some antiacid and another med to relieve the symptoms. My pains started a month ago, it would start like small aches that would come and go... but lately it s been more common and a bit prolonged aches. I don t know, if I should be alarmed or if it s just somethig really simple to cure. Please, help.