I have an almost 5 yr old male child who in the past 2 months has begun to vomit after eating. Sometimes it's in the middle of eating and other times it's a few hours later and once in the night. When he vomits, there is no mucus, no fluid, just undigested food. He was just tested for food allergies and he had no reactions. Is there another avenue I should try? Gastrointestinal problem? Ulcer?

He is a very active, normal, fun-loving boy who doesn't have a care in the world. However, he has since this started, been skittish to eat his favorite foods for fear of vomiting. He often complains that his belly hurts. He has also been having loose stools; not quite diarrhea but more loose than normal.

What has the doctor said you should do next? I think they should have done more than just test him for allergies and then pass it off when they couldn't find any. There is obviously something going on. Maybe it's time to find a different doctor.

Chronic appendicitis?? (Pain first, vomiting second, fever third are the acute symptoms)
Meckel's Diverticulum, rare congenital condition sort of near the belly button (2% of population, around age 2, mostly males)
Just two guesses... but his condition sounds very worrisome.

Has he had ultrasound, CT, any kind of scan??

There are so many possibilities, and I'm shocked that the doctor only tested for allergies. I would find another doctor.

I can think of several medical issues and even physiological issues that cause this.
Why is he not back at the doctors for more testing