Poo poo

Hi mommies.. Nahihirapan magpoop baby namin.. 6months na sya and kakaupgrade lang namin ng milk nya pero same brand lang since new born sya (similac). Then na-start narin namin sya pakainin ng solid food and water.. Please give me tips kasi umiiyak sya pag nagpoop then may dugo na din poop nya ?