I ve been farting really bad lately, almost constantly for the past 2 days. My right side, at the bottom of the rib cage had a sharp, clenching pain earlier today for at least half an hour and that happened again tonight. While the second sharp pain happened, I was going to the bathroom normally then started having diarrhea , I also drink a lot of Diet Coke and I have for a while now, I m 17 years old.