My son threw up everything too for 36 hours, incl water and medcine! with major stomach cramps that he lied on the floor in pain.
Doc gave him塞肛止嘔葯. U shd ask for塞肛葯. He needs to replenish with mineral powder. Doc has that too.
I only gave him soda biscults (little air and fat, no butter) and plain water, as the doc say bread and congee will make him vomit more (as congee is water, water makes him vomit).
Shd not drink milk when 疴嘔. You can try bean milk powder (豆奶粉), but use half portion to test first.