Burning pain in upper stomach?

For the last 3 years about once a year I've had this somewhat intense burning pain in my upper stomach that seems to last 24 hours. The second time it happened I was hospitalized and given morphine because the pain was so intense...after a day or so all the pain slowly went away and didn't come back. A year later now it is happening again (although not quite as intense as last time i still cannot sleep).....Originally I thought maybe it was acid reflux but I took Tums, Gravol and Pepto Bismal (not all at once) and it didn't so much as help a bit. No matter what I eat or drink the pain does not subside until about 24 hours or so has ped. Is it still possible that it is acid reflux or an ulcer or something? I just find it so strange that it only happens once a year...I ate 2 peanut er and Jam sandwiches with milk 3 hours before the pain started this time...the previous time I had a bowl of Bran Flakes....