Diet changes-
Diet change is the first thing I recommend.
Before you do anything, I recommend laying off dairy products (milk, cheese, yogurt and ice cream) completely for 2 weeks to see what happens.
If it doesn’t work, then avoid or minimize foods that can cause excess gas- beans, lentils, broccoli, brussels sprouts, salads, cabbage, apples, pears, artificial sweeteners especially sorbitol, high fiber sources such as bran cereal, etc.,
One misconception is that if you have IBS, you need to eat lot of fiber which is not necessarily true. Fiber may actually make your gas/bloating worse.
Raw vegetables in general cause more gas. Cooking the vegetables, especially boiling will eliminate some of the chemicals that cause gas.
If you are a big chewing gum user, avoiding it may help. You suck lot more air if you are drinking or eating too fast. So slow down.
Low-FODMAP diet-
FODMAPs are different sugars in our foods that are hard to digest and can ferment in the gut to produce excess gas. Foods low in FODMAPs may help minimize the gas. This diet is little hard to follow in the beginning but if you already tried all of the above, you may need to go on this special diet.
Activated Charcoal-
Charcoal tablets sometimes help absorb the excess gas.
Probiotics-
Trial of probiotics such as Align or IBplus may help in some people.
Digestive Enzymes-
Try digestive enzyme tablets that are available over the counter to see if they help. You will know it within few days if it is helping or not.
Small Intestinal Bacterial Overgrowth (SIBO)-
In some cases, especially if you had abdominal surgery in the past, you may have excess bacteria in your small intestine that can produce gas. Taking certain antibiotics may help relieve excess gas at least for few months.