Hello there, my daughter is 15 mths old. She has been constipated for months now. She is breastfed, has some formula & eats a really good diet , lots of fruit, vegetables & wholegrains & drinks plenty of water. She is constantly passing gas & is full of wind. She is obviously very uncomfortable, drags her knees up to her belly a lot & is very irritable. Her poop is very dark & very foul smelling & looks a bit like greasy play dough. She alo gets hives . What could it be?