Pain beneath the rib cage immediately after eating? and less painful when drinking a little? what it could be?

Some possibilities..: Under the right rib cage are the liver, gall bladder, first part of the small intestine, the muscles between ribs, the diaphragm, etc... On the left side are the stomach, spleen, diaphragm (muscle for breathing), a part of the colon (large intestine), the tail end of the pancreas, etc... A doctor can evaluate to look for gallstones, acid reflux, pancreatitis, and other possible causes.