The schilling test is performed to determine the cause of-
Schilling test. The Schilling test is a medical investigation used for patients with vitamin B12 (cobalamin) deficiency. The purpose of the test is to determine how well the patient is able to absorb B12 from their intestinal tract Ref Davidson edition23rd pg 805
Lactose malabsorption
Fatty acid malabsorption
Amino acid malabsorption
Cobalamin malabsorption
G.I.T