Nutramigen and Mucous in stool

Hi all!

My 10 week old has been on Nutramigen since she was 6 weeks old due to suspected CMPA, she was on gentlease and that made her extremely fussy, colicky, had painful gasses and couldn’t eat more than 1oz at a time. The day she started Nutramigen she was a new baby, the screaming and crying stopped. She started sleeping through the night just waking 1 time to eat, Nutramigen was a life saver! After 2 weeks on the new formula she started having blood and mucousy diapers (she never had them before) and only had blood in them 2 days and also started spitting up a lot more than before, she still is a happy baby and good sleeper. I know that having mucous and blood in stool is a reaction to the ingredients in formula so why isn’t bothering her, and why isn’t she crying in pain? Should I leave her on it or try Elemental formula? Is having mucous in diapers normal? Has anyone run into a similar situation?