Aspartame, Mannitol, Acesulfame K, Colors (Red 40 Lake, Yellow 6), Sucralose
Artificial sweeteners and sometimes artificial food colors make people's insides go Pow!
It certainly happens to me. I avoid aspartame, acesulfame K (acesulfame potassium), sucralose, xylitol, and stevia. I would rather just have something unsweetened and unflavored because those don't taste good and they make me feel like I'm going to spontaneously combust.