What can be the cause of persistant, excessive gas? no known food or drug allergies, no predictable pattern. worse in the morning when i wake up.

Talk w/your doctor: Talk with your own doctor about this -- but you may have some food intolerances or even some bacterial overgrowth in your gut creating excess gas in their activities. These bacteria (many of which are friendly to us) need to be in balance. Overnight they can be digesting up a gassy storm. You may benefit from a good probiotic taken daily for awhile to help your gut's "good" bacteria win.