baby pooping too much?

Dominique • Myles John 3/8/16. Micah Robert 6/29/17 baby girl due 10/8/20
My son went from pooping 1-2 times a day even sometimes 3 to now for the past week pooping 5/6 times a day. It causing him to get diaper rash really bad that we have been trying to keep up with but keeps coming back. He is almost 11mo old
Anything I should be concerned about?