38y male with foul smelling gas for 5 weeks straight. no pain, nausea, change in stool or blood. otc (gasx beano lactase) did not work. no change to diet in past few years so wondering what could be the cause and best course of action?

It may have to do with changes in the type of bacteria in your gut and their effects on the food you eat. You may want to increase fiber in your diet like in salad to push some of the bacteria out by a rapid transit. You could combine that with use of probiotic probably in yoghurt or similar food that has healthy bacteria.

It is not unusual for the odor of the stool to change at times. Since you have no other symptoms associated with it, it may be difficult to pinpoint is cause. A simple suggestion to increase the amount of fiber in your diet, along with extra liquid, may be helpful. Otherwise, return to see your primary doctor or your G.I. doctor If the symptoms persist. Good luck.