So my new pup Rocco pooped for the first time yesterday, well he squirted, not pooped. I had to give him a little enema because his tummy was hard and he hadn't gone #2 for 2 days. He went and felt MUCHH better. I've been trying to give him soft food, to balance out his bowels but he wants nothing to do with soft food. He ONLY wants his and Coco's kibble. It's high quality kibble, his Innova for puppies with Nutro for puppies and hers is the same but for adults.
What can I do to make him poo on his own? I tried mushing his kibble mixing it with gravy, or mixing it with canned food (which I DON'T EVER use but needed something this time). I've tried EVERYTHING and he refuses to be treated like a baby, he wants to be a big boy and eat his sisters kibble

What can I give him to make his poor soften up?