Infant has diarrhea and spits up

My daughter was born in July and is 5 weeks old. Since bringing her home from the hospital she's had diarrhea and she spits up. Her brother (now 1.5) never spit up once or had diarrhea so this is new to me. She's only breastfed and the pediatrician told me to cut dairy from my diet (devastating), so I did. It's been a month and no change so far with her poops or spit up. The pediatrician ordered a stool sample to check for bacteria, so that is pending. I've mostly cut out eggs now too and no difference with that either. My aunt came over yesterday and suggested that I take probiotics, so I started that last night, but too early for a change. Please let me know if you have any feedback for me!!! I want her to just feel better. Thank you!