I Have A 7 Year Old Nephew Who Was Diagnosed

I have a 7 year old nephew who was diagnosed with 3 pinhole ulcers. Meds don't work and he is spiking a fever and the hospital sent him home, after being there all day ( by GI specialist) saying they don't know what it was. This is week number 4..Ct's done . xray's , upper endoscopy done...help