Suggest Treatment For Bloating, Vomiting And Inflammation In Stomach

My son has seen his dr. and oncologist for his lymph nodes in his left side of his stomach are in flamed but his oncologists said he doesn't have cancer..and all he did was blood work and told him to go back to his primary dr. and now his left side and his whole stomach looks bloated and he starting throwing up and his has breath is starting have a smell even when he brushes his teeth can you tell what could be please or tell me what to tell the dr. Im very worried mom. Thank you