My son, at 6 months, is a good sleeper, but will go through periods where he wakes up more frequently in the night. I feed him every time; however, this is in-part to help maintain my milk supply - plus, now that he doesn't require a burp, he falls right back to sleep. I do co-sleep, however, and it enables me to get much more sleep when he wakes up in the night.
If he is waking up due to gas, check your diet and make sure that he's getting a burp in before heading back to sleep (mine burps when I sit him upright - he stopped needing a burp at about 5 1/2 months). The other thing that helps my fella stay asleep is that I still swaddle his arms and/or use the Magic Merlin Sleep Suit. I find that without it - he startles himself awake. If you are concerned, you could try to rule out an ear infection. But seriously, check your diet - I found that when I started eating brussel sprouts, it affected his digestion and caused him to wake in the night.