I haven't had much soda since I came back to college. (Less than 4 small glasses in a week.) Soda has always made me feel gassy, but tonight I was craving some, so I went down to the store and got a Pepsi. Within 15 minutes of drinking half the bottle (about 10 oz.) I had to bolt for the bathroom. This really hasn't happened to me before. Why would it make me have D when it really hasn't before? And was it actually the soda? Or was it something else I ate? 15 min. seems like a very short time for anything to go through my system.