Rylee was... is the same way but now shes going once every two or 3 days but its very large. My doc told me.... which I think is wrong... that the hospital will not do anything about it until she hasn't gone for more then 3 days!
but while we where dealing with her jaundice she was on formula and thats when it started because about the same time we changed the formula and then we added BM which helped but then my boobs dried up

and now I have been trying water and water with a little but on apple juice..... but nothing really works to great.
but thats all I know. Maybe it will help your little one.
oh yeah... this doesn't work for Rylee but it does for some babies.... you could try a rectal temp. that might stimulate her to go