Baby hasn't slept in 3 days

I just got off the phone with my sister who lives overseas. Her 1.5 month old baby has been diagnosed with reflux. I have had 2 kids with reflux, so I have some experience with it.

But her baby hasn’t slept in 3 days, only eats for 5 min, and is spitting up horribly. She just started her on bethanichol and has given her 2 doses of 0.3mL. She is now having horrible diarrhea.

I told her to get her to a doctor today if she can, but I don’t know what else to say. My kids never had it this bad.

Thanks for your help!