Potty training

My son is 2 years old, and we’re working on potty training. He has pee down pat; will initiate that he has to pee and ask us to take him to the potty so he can go. He is terrified of pooping though.. it’s gotten to the point where he’ll hold it all day and then poop in the middle of the night. I don’t know where to go with this 😕 I don’t want to start night training if his body isn’t ready for it, because he always wakes up wet. But I hate the thought of him possibly pooping in the middle of the night and sleeping through it.. he hasn’t once woken up through it, he just poops and sleeps in it until morning. I hate that.

What do I do??