labeled cobalamin to appear in the urine because it will remain in the intestine and be passed into the feces. Stage 2: vitamin B and intrinsic factor If an abnormality is found, i.e. the B12 in the urine is only present in low levels, the test is repeated, this time with additional oral intrinsic factor. If this second urine collection is normal, this shows a lack of intrinsic factor production. This is by definition pernicious anemia. A low result on the second test implies abnormal intestinal absorption (malabsorption), which could be caused by coeliac disease, biliary disease, Whipple's disease, small bowel bacterial overgrowth syndrome, fish tapeworm infestation (Diphyllobothrium latum), or liver disease. Malabsorption of B can be caused by intestinal dysfunction from a low vitamin level in-and-of-itself (see below), causing test result confusion if repletion has not been done for some days previously. Stage 3: vitamin B and antibiotics This stage is useful for identifying patients with bacterial overgrowth syndrome. The physician will provide a course of 2 weeks of antibiotics to eliminate any possible bacterial overgrowth and repeat the test to check whether radio-labeled Vitamin B12 would be found in urine or not. Stage 4: vitamin B and pancreatic enzymes This stage, in which pancreatic enzymes are administered, can be useful in identifying patients with pancreatic insufficiency. The physician will give 3 days of pancreatic enzymes followed by repeating the test to check if radio-labeled Vitamin B12 would be detected in urine. Combined stage 1 and stage 2 In some versions of the Schilling test, B can be given both with and without intrinsic factor at the same time, using different cobalt radioisotopes 57Co and 58Co, which have different radiation signatures, in order to differentiate the two forms of B. This is performed with the 'Dicopac' kitset. This allows for only a single radioactive urine collection. Complications Note that the B shot which begins the Schilling test is enough to go a considerable way toward treating B deficiency, so the test is also a partial treatment for B deficiency. Also, the classic Schilling test can be performed at any time, even after full B repletion and correction of the anemia, and it will still show if the cause of the B deficiency was intrinsic-factor related. In fact, some clinicians have suggested that folate and B replacement for several weeks be normally performed before a Schilling test is done, since