elimination communication.
Practicing Elimination Communication - DiaperFreeBaby
others might have better links than that, but basically u watch your baby for cues about when they need to pee or poo and then u hold them over the toilet (in a specific supported way). i sort of think of it like when u get a new puppy u watch it constantly and when u see it sniffing around u put it outside to potty, or when it wakes up, or after a good hard play etc. so there are similar situations and cues you can see the baby do. i havent done it much w payne since he is not mine but i will def be trying it with my future babies.