Breastfeeding and caffeine

Angela
My LO has had 4 poopy diapers since early this morning. Three of them in the last 20 minutes. He had none yesterday except for a few, what my SO and I call, sharts lol
The only thing I have changed in my diet is a Pepsi that I had yesterday. I usually have about 2-3 cups of coffee a week so I am consuming some caffeine but could the Pepsi have been too much for his little belly? Anyone else experience this or have any insight?