IMO, Metamucil is the worst fiber supplement for folks with IBS A or C. I took it for years and ended up with a terrible impaction. If you must take a fiber supplement, you should look for a soluble fiber like Benefiber.
In my case, all fiber supplements are the kiss of death. They completely plug me up and leave me with trapped gas. My solution is to get my necessary fiber from food.
I too suffer with gas and I've come to conclusion that there is not much I can do about it. I've taken the anti-spasmodics but found that the only thing they do is constipate me. Some folks have found relief with teas such as peppermint or fennel, but they don't work for me. What does seem to help is belly massage, as the above poster mentioned, heating pads, and movement. Sitting for long periods of time often worsens gas. I have also found relief from laying on my left side with my right knee pulled up to my chest. This posture works best right after a meal.
Yes, peppermint bothers my acid reflux as well.
Have you tried taking miralax or stool softeners?
Gas is created by bacteria in the bowel. It unfortunately doesn't matter (in some cases) how many BM's you have or how much gas you are able to pass - if food is sitting in your gut beyond it's expiration date, it will create bacteria which will create gas. In the case of IBS, a gut that spasms rather than propels will keep the contents from fully evacuating, thus causing the remaining matter to create gas. Some of us are just lucky that way, I guess!
I don't like to do this often, but I have found that Mylanta is helpful for relieving trapped gas. The magnesium in mylanta will often get things moving a bit too much though so it's important to stick to the recommended dosage.