I had to respond because one thing none of the doctors even told me about before my surgery was Gas!...For the first month and a half or so after surgery, I had gas ALL the Time! :(. And it was definitely loud--the "my stomach is growling" excuse would definitely not work. It literally sounded like a whoopee cushion or something, almost 10 times per day... I was so alarmed because I thought how can I go throught the rest of my life making these sounds?? But the people here told me it would eventuially go away and it has almost completely!
Now, I can't even remember the last time I had a gassy sound (I am about 3 months postop)--it may happen once every 2 weeks for me, and now the sound is so quiet that if I am in a room with people talking or a radio on, no one would ever hear it, really. I can always feel it coming, which is good bc you can put you hand over the stoma and muffle it as other said. I don't even do that since the sound is so quiet now. The only thing that I know gives me gas is ice cream, and thats because I am lactose intolerant!
Good luck. If you have gas at the beginning, it will surely decrease greatly as you recoup. :)