If you are a woman you need to be checked right away for ovarian cancer. This was a symptom my mother developed that we teased and made fun of her over for months....it turns out this is a symptom of ovarian cancer. I sure hope I am scaring you for no good reason, but I couldn't not comment.
Look at what you are eating, this is usually the culprit. Stay away from the artificial sweeteners malitol and sorbitol. Remove one thing from your diet and if it's no better in a few days, add it back and take out another. There are over the counter medications that dissolve gas in the intestine, Phazyme is one. Take care...