There's a webcomic called "Pawn" (www.pawn.se) that I recently stumbled across. A running gag throughout the series is that Aynah gets gas from the rations she eats.
http://pawn.se/Webpages/Comic/Pawn%2002/pawn_02_12.jpg
http://pawn.se/Webpages/Comic/Pawn%2002/pawn_02_13.jpg
http://pawn.se/Webpages/Comic/Pawn%2004/pawn_04_15.jpg
http://pawn.se/Webpages/Comic/Pawn%2005/Pawn5-(10).jpg
If anyone knows of any other farting comics, feel free to post them. ::great