A.H.
What have you done in the home or what has happened in his life recently? The smallest change can stress a child out (Yes, children suffer stress, too. My son was extremely stressed out at daycare over an event and I removed him due to the aftermath.)
My SIL/BIL tiled their kitchen and was remodeling and this caused my nephew to do the same - including bed wetting.
Try talking to him and maybe you can see what is going on. Punishing him, forcing things will not help the situation (long-term). This just adds to HIS frustration and stress.