Baby's symptoms mymic CF but is not CF

My baby son is fifteeen months old and weights fifteen pounds.  He was born early weighting two and a half pounds and had a hard time starting solid foods.  He only would take breast milk for some time.  Now he eats lots better but is often sick and still isn't gaining weight well.   For this reason we have taken him to a GI doctor.  My son's blood work showed markers for CF.  He had fats in his stool and low pancreatic enzymes.  This made sence to me as he often has a cough.  However when they gave a sweat test, it came back negative.  No CF.  What mymics the symptoms of Cf but is not in fact CF?   Also the doctor said there were some abnormalities with his red blood cells.  In addition he sometimes has elevated biliruben.  Additionally his testing shows high calcium, protein, albumin, and AST.  Low Igm serum.  Under CBC with differential-  high RBC, RDW, and platelets.  Low hemoglobin, hematocrit, MCV, MCHC, and MCH.  Under automated % Eosinophils and Eosinophils, abs count are both high.  His fecal split fat is increased and trysin fecal is abnormal.  This looks to be perhaps a GI and blood disorder.  If anyone can help I would be so grateful!

[CalGal]

You may want to check out gallbladder issues, pancreatic issues and celiac disease.