I agree with Sharon.
Over the years, you may have become sensitive to something, like dairy, wheat, yeast(beer, wine, etc.), sugar-free sweeteners, sugar, sodas. Make sure you aren't swallowing air when you eat, don't drink through a straw, smoking causes gas from swallowing air. Things like that, I know my system has changed over the years to food. Also, be careful for gas producing foods like cauliflower, broccoli, eggs, ice cream, green peppers, soda, baked beans and lentils, etc..
Food diary time....or you might have a bacterial overgrowth.....you need yogurt and probiotics for that. I use Turmeric for an anti-inflammatory myself, if that's a problem. Good luck!