E.C.
My daughter had the exact same problem and was on the exact same softener as well. Fortunately, she was potty trained at 22 months and the constiaption problem cam eafter her potty training, but still was an issue. After, her first severe poop tradegy she began holding back and would end up having atleast two accidents a day. This was hard because I work so it made a mess for her daycare. I would talk her through it each time and she got special prizes every time she went #2. Eventually, we worked through it and she wasn't fearful anymore. I would definitely start trying to work with him because he is three and he knows the difference now. Be very encourgaing and rewarding to him. I would start off haveing him atleast start going pee in the potty. Because of his fears and having been in the same situation I wouldn't push him too hard on the pooping yet. Definitely, start though because the longer you wait and the older he gets the harder it's going to be for both of you. Hope this helps!