Baby is 3.5 months old and poops brown water

Hi everyone,

Our 3.5-month-old daughter has been having loose stools for 7 days now. It started a week ago; she barely wanted any food and had real diaper explosions with diarrhea. She was also vomiting everything up. We called the doctor's hotline and visited the GP twice, where she got ORS, but she didn't improve and wouldn't drink the ORS. She wasn't dehydrated, had no fever, and was active and quite cheerful. However, she barely sleeps during the day, whereas she used to be very easygoing and always took her naps.

Then, after 7 days of diaper explosions, we went back to the doctor's hotline and saw the pediatrician. He said she wasn't dehydrated and mentioned a stomach infection. She was supposed to drink apple juice instead of ORS, but she wouldn't do that either.

Now, 7 days later, she's becoming more cheerful and drinking much better, but her stool has changed from diarrhea/mush to just brown water over the last 2 days. She's just pooping brown, strong-smelling water with absolutely no solid content left. You'd think it was urine it looks so much like that, but it's not. She does have good wet diapers again.

Does anyone recognize this? It could last up to 10 days, but she should be improving. The drinking is indeed getting better, but the stool isn't. Does anyone know about this?