<s>[INST] My grandson, almost 3 yrs old dob-12/30/2011 he is loosing weight down from 25.6 to 23.5. He has had numerous blood tests - all within normal ranges for whatever they were testing for. Stool tests showed no blood but elevated fat in stools . He is going to have his gi scoped Thursday . What else r they looking for . Could there be a cancer that hasn t shown up on blood tests? [/INST] Hi, I am Chat Doctor.  You have not mentioned associated symptoms if any. First to rule out is diabetics mellitus and also hyperthyroidism in an asymptomatic child.  Cancer without any clue in examination and investigations is unlikely but can not be ruled out. Any chronic illness will have other sign and symptoms, but common disease like tuberculosis needs to be ruled out. Gastrointestinal endoscopy is for evidence of any malabsorption and any lesion (which is not showing up in blood reports) to reach a diagnosis. Hope this answers your question. If you have additional questions or follow-up questions then please do not hesitate in writing to us. I will be happy to answer your questionsTake care. </s>