My son is 2 years old and threw up brown stuff chunks of brown and liquid looking stuff and hasn't ate nothing that would look like what he threw up. He is also pooping a lot 2-3 times a dat but it drinking and eating fine. What could this be? I read fecal back up but he's going several times a day.. He has woke up twice screaming but it's more of a fake scream for attention than a pain scream.