OK, this is going to sound really weird, but i used to hold dd1 over a sink, encouraging her to do a poo before she would go down for naps and bedtime. This went on until she sat on a potty at 13 months. I would also press (not hard of course) her legs to tummy to get gas out and if any poo would come out, great
! But the holding over the sink worked really well for us cause she went through a stage when she would wake up very soon after a nap with a dirty diaper. With dd2, she's a little more predictable - she tends to save her poos for 5am wake ups
. I am not sure if I like that thou cause I have to try to change her with as little stimulation as possible, but not much I can do about it.
HTH
Layla