I have two kids (3 1/2 years and 10 months), and I generally carry a changing pad plus diapers and wipes in a plastic bag thrown into my large bags. That's one reason I carry my MJ Stellas so often, they work for carrying all the gear I need. I've never been one to carry a seperate diaper bag (although we have one in the car, and my partner carries it when he has the kids).