have you tried miralax? we did that for a about 3 days (half the adult dosage) just so she could get some relief.she was like a new little lady. i also got some flaxseed/oatmeal cookies and those seem to help things move along as well. i give her at least half of one everyday now. flaxseed bread works good too.
i am a fan of the toddler formula honestly. it just seemed to help her transition easier. good luck on your research though! i never looked into any of that once we realized the 2% was working out ok.