constipated

hello!! my 1yo baby having constipated for abt 3days and 2 of the days, there's blood in her poop. her poop like pebbles-like. she recently refused all milk and plain water. she only wants drinks that unfamiliar and new to her. her food intake also decreased from 3 times a day to 2 times a day. should I bring her to kkh for checking? 15/2 is her 1yo vaccine at polyclinic