Sounds like the beginning stages of biliary colic. I used to get a lot of pressure under my right rib, not pain after eating but especially at night. I would be extremely bloated as well. I would go months without anything like that happening again, until it became more and more frequent and then became VERY painful. I ended up going to the ER where they diagnosed me with biliary colic (gall stones) I refused the surgery that time and they told me if I came back with so much as a fever I would have emergency surgery. Well 6 months later, I had very ill and unable to eat for 2 weeks without getting very ill (sharp stabbing pains under my right rib that put me in so much pain all I could do was lay there and cry.) I went to the hospital, I was in so much pain I was sobbing and trying to tell them I already knew what was wrong it was my gall bladder. They did an ultra sound and blood tests, sure enough my white blood cell count was through the roof as the doctor described it, I was dehydrated, had an infection in my gall bladder from my common bile duct being blocked. They kept me in the hospital and gave me morphine for my pain ( I think that was a little overkill because my brain seemed to be tingling after they gave me it and I was loopy.) They pumped me full of a grand total of 10 bags of fluids and the next morning at 6am I went into surgery. I am not sure what time I came out of surgery but I went home that same day at about 7pm.

Sure sounds like Gallbladder to me. Stones it may be also. Either way you have to have it looked into. This is something that should not be looked over and think it will go away. Although not an emergancy issue, it sure can give you a heck of alot of discomfort and pain. Now go get it taken care of.