For the past three months I have been waking up with a pain under my right rib cage that feels like a knife. I have had CT scans, Endoscopies, and a Colonoscopy. I was told I have Barrett's esophagus, Hiatal hernia, acid reflux, IBS, gas and diverticulitus. I have been on Nexium 40mg twice a day, but I still wake up with the pain. Could this be caused by an ulcer ? I also noticed that the pain seems to go away after a bowl movement or if I eat. Any help would be greatly appreciated.