I've narrowed down my occasional bouts with intestinal gas to sugar alcohols. Maltitol was the most common sweetener in the energy and protein bars I used to eat -- ThinkThin. I switched to bars (Clif and Larabar), gels (Clif mocha with caffeine) and electrolyte powders (DripDrop) that use regular sugar, dextrose or glucose. No more problems from cycling fuel. And I've had no problems with maltodextrin.
Any other issues with intestinal gas and mild stomach cramps were due to other stuff I eat. One big offender for me is milk stouts, but I usually drink only a few of those during the winter brewing season. And I have some lactose intolerance, so I've cut way back on most dairy other than yogurt, which doesn't cause me any problems. But I'll have a chocolate malt once or twice a week at Braum's with burgers. And I'll try anything once so occasionally something that tastes good going in causes problems later. I've narrowed down my regular diet a bit for convenience, so I don't need to worry midway through a long ride.