creamaffin syrup rarely have side effects for a short period of consumption but it is not recommanded to take it for a long time.
go to the root cause, your son is only 2 years old
so.... avoid regular eating of fast foods
kurkure and other bakery items.
increase fibrous food in his diet like green leafy vegetables, fruits,cereles etc
proper consumption of water is also important
you said that he has hard stools sometimes with blood, to avoid this u can do some home remedies
like , give him makhkhan (freshly prepared at home) twice or thrice a day!!
soak 10-15 black currants with a cup of water at night and in the morning crush them in the soaked water with hand and ask child to drink the whole,
this will help to overcome the constipation
problem(also it will increase appetite of child)
last but not least apply Jatayadi Ghrut (ayurvedic medicated ghee)at the anal ring every time he goes and comes from toilet.
all these measures will help to overcome above said problems!!
Wish a good health to your son!!