Endoscopy shows erosions - that can be because of multiple causes
Biopsy should be done to look at the cause
Vomiting can be because of multiple causes
Systemic infections
Renal injury
CNS causes
Vestibular involvement
Local causes and infections of the GI tract
Inflammatory causes
Obstructive causes
Cyclical vomiting syndrome
All this needs to be considered and to be ruled out step wise
Next Steps
Endoscopy with biopsy, cect abdomen, amylase lipase levels