Say NO to all filters. I believe the ventilation system installed in bags still has a long way of improvements. You never know when the filter would clog. It can last for 2 days and sometimes a few hours. I prefer to use the ventless bags. And if yours is vent-installed, you can block it. You can use any sort of tape and completely cover the vent. I use the new Sensura Mio and they still haven't released the one-piece vent-less ones, but each box of bags comes with a board of tape pieces that typically fits the vents. Awesome bag but vents, nah.
Now another tip that can reduce gas by 60-70 percent on whatever you eat is charcoal. They really work. If you managed to get the highly absorbent in capsule form, you have to taper the capsule as it may not dissolve at all. So, stick with tablets or if you don't mind breaking the capsule then that's fine. The highly absorbent ones only come in capsule forms and yes, they have higher absorbent efficiency.
Don't expect that you will find less gas in the same day you use them. You can only notice the difference after 5 days of continuous use. What I mean with continuous is after every single meal you have. Once there is charcoal in your digestive system on a consistent basis, the gas will reduce significantly. From what I read, charcoal does not interact with the body at all and has 0 absorbance in your system. All it does is suck out gas that builds up and pass out in the bag.
Having said that, the capsule cap does get absorbed in your system and your body clears it up by the liver. As it is something that you will be using on a day-to-day basis, as well as taking the maximum dose (that's what I recommend for the highest efficiency), I would recommend using the capsule (high absorbent formula) only when you know you messed up your diet. Like beer, garlic, onion, beans...etc. Otherwise, stick to the tablets.
You will still have 20-30 gas that wouldn't get absorbed by charcoal and the only thing you can do for this is either to ignore or to burp the bag as some ostomates said above.
Another advantage of charcoal is that you won't see this fascinating rainbow colors in the output anymore...lol the output will be just black (don't get scared when that happens, it ain't bleeding).
Try and you'll see.