Could Switching My Toddler From Nan Perlagon To Nido Be Causing His Constipation, Given His Poor Appetite And Picky Eating?

Hi Dr my son is 1year 2months and I ve just changed him from nan perlagon to nido so I ve realised that he s always constipated,he doesn t normally eat during the day nd he s very choosy when it comes to food....is Nido the reason why he s always constipated? I m worried that he might develop piles.thanks