What Causes Abdomen Pain Along With Watery Stools In A Child?

My two year old daughter threw up a couple times of just bile last night and has been having many runny almost watery looking poop all week. She's had three today so far and it's only 4pm. It just looks like brown water and it really stinks. Her tempurature is 35.3'C. She keeps complaining her belly hurts. Any ideas? Have given her Tylenol Kids but I fear there's more to it than just giving her a Tylenol. She's also very pale.