Toddler constipation

Hi,
I need help regarding my 3.5 year old daughter.
She has struggled with constipation for over a year now.
With the help of diet, more liquids, vitamin C she is going pretty much everyday now. Does skip a day here and there but is better than before where she wouldn't go for 3 days.

Even though she is going often her stool is quite large and dark colour and sometimes she cries after passing her stool says it hurts.

Her diet is pretty good, no dairy, eggs or soy.
She is tall but thin built, does not put weight on which has been an issue since birth.
- loves ice cream, eggs and dairy ( don't give to her now)

She also has dark circles, gets full after few bites of food.

Personality wise she is happy girl, very friendly with everyone, loves chatting and playing games and also very determined.


Other info:

-Born at 37 weeks
-NICU for poor weight gain,
-breastfed till 6 months then on formula which she spit a lot of out. -Had heart murmur which required surgery so had anaesthetic and antibiotics.
- mild jaundice at birth
- low iron at last blood test
- fully vaccinated


Thank you.
[Edited by akira on 2020-06-16 09:32:52]