Mommys who use prune juice for their babies 4 months (& under)

My Lo has been having constipation issues for two weeks now (she will be 4 months on Oct 8) It started with her not going every day when she has since birth....she would eventually go at some point within the next 24-30 hours but it would be harder/thicker then usual. Also she started to get really gassy and super fussy! She stopped sleeping through the night and would fuss most of the day. This went on for 2 weeks before going to the doc were she told us just to give her 4oz of prune juice a day for a bit. Well I gave her 2oz yesterday and within 15 mins out came a thick clay like chunk with more normal poop behind it.

I gave her 2oz today and had a massive diaherra blowout!!! So 4oz a day is def out the question!!! She won't be getting any more today....but how much do you give just to keep regular??? And do you dilute a bit?

I was thinking to maybe go down to 1 oz a day....and dividing it up twice daily??