3yr old. Calprotectin 165. ESR Sed rate 26, Immunoglobulin A 183. Burr cells 1+. Poor weight gain. Could this be normal? GI related?

Not normal. Elevated CRP and ESR suggest an inflammatory process. With a history of pneumonia and adenoidectomy, it sounds like your child has had sigificant illness. With poor weight gain, both GI and Immune dysfunction should be evaluiated by your child's doctor.
Question for peds. You should ask pediatrician about this, not urologist. .