He's constipated. Bananas, rice, applesauce, and cheese can be very constipating. . .along with cow's milk (once you wean him). Fruits that start with P are very helpful, prune juice mixed with his cereal along with feeding him the prunes can help. More water will also help. Does his poop have an ammonia smell to it? When that happened with my daughter, my ped told us to increase her water and that helped.
All 3 of my kids (11.5 and twin 5.5s) have been on Miralax because we just tend toward constipation no matter what our diets. I've recently been able to back off the Miralax with 2 out of the 3 and my one who is a huge water drinker still needs it. Go figure!
I would suggest eliminating the applesauce and if that doesn't make a difference, mix his cereal with prune juice to see if that helps--along with still feeding him the prunes.
Good luck!!
T.