My 10 week old has been on Ranitidine for about six weeks now. For the past two weeks, she has had green poops that are sometimes watery, sometimes mucousy. It seems the usual causes are food sensitivities, stomach bugs, or foremilk/hindmilk balance, but I was curious if it could also be a side effect of the medicine. Has anyone noticed any impact on baby's poops as a result of Zantac?

Also, with regards to food sensitivities being the cause, is it possible for the green diapers to start at one month old or would we have seen them from the start? (No changes to diet)