if u've not found the solution yet, then try asafoetida (available in any indian store or neighbouhood minimarts sometimes) . its natural and very safe even for infants. whenever my 3 months baby doesn't poop for couple of days or cries due to flatulence, i either apply a pinch of asafoetida mixed with 1 tbsp warm water, around his navel or if too bad constipation just give same amount mixed with few tbsp formula milk. its bitter so the child will not drink it willfully but force it with a spoon and he'll be alright in a while.