My 3 month old who is breastfed only poops once every 5 days and by the last couple days she is so uncomfortable, what can i do to fix it or help her?

Breast feeds: Breast fed infants can go a little every feed or overflow a diaper once a week. If it is soft when they go i don't worry about it. Babies fuss for a lot of reasons including gas, so irregularity is not always the cause. If stools are getting hard, i often try full strength prune juice, 1oz once or more/d.Takes about 3d to get things moving.

Breastfeeding: It's not uncommon for breastfed babies to have stool frequency as your baby does. Usually, they tolerate it pretty well and with time as you introduce new foods it gets better. The discomfort you are referring to may not necessarily be related to it. Of course, you are the mom and know your baby better, but from my experience they do ok having that bm routine.

Go to peds doc: I think you should see your baby's pediatrician because usually babies have stool like clockwork. They may rule out something serious like hirschprung's disease where they get a mega colon and unable to get their stools through.