Schilling test

A 67-year-old lady was found to have low B12. She underwent a Schilling's test and the Stage IV test was positive. What is the diagnosis?

1- Pernicoius anaemia

2- Coeliac diseas

3-Bactrial overgrowth

4-Crohn's diseas

5-Pancreatic insufficiency

The patient is given two doses of Vitamin B12 (cobalamin). The first dose is radioactive and taken by mouth. The second dose is not radioactive and is given as a shot 2-6 hours later. Urine is then collected over the next 24 hours to measure whether Vitamin B12 is normally absorbed. If Stage I is abnormal, Stage II may be done 3 to 7 days later. In Stage II, patients receive radioactive B12 along with intrinsic factor. Intrinsic factor is produced in the stomach and binds to Vitamin B12. Stage II can tell whether low Vitamin B12 levels are caused by problems in the stomach that prevent it from producing intrinsic factor. If a Stage II test is abnormal, a Stage III test is performed. Here, the Stage II test is repeated after the patient has taken antibiotics for two weeks, and can tell whether the abnormal growth of bacterial has led to low Vitamin B12 levels. A Stage IV test determines whether low Vitamin B12 levels are caused by problems with the pancreas. Here, the patient is given pancreatic enzymes for three days, followed by a radioactive dose of Vitamin B12.If there is a problem with the stomach's ability to make intrinsic factor, Stage I of the test will be abnormal and Stage II will be normal. Both the Stage I and II Schilling tests will be abnormal in patients who have problems in absorbing Vitamin B12 and intrinsic factor in the small intestine.

stage I normal: no PA
stage I abnormal: ? PA
add IF,
stage II normal: PA
stage II abnormal: ? BO
add Abx
stage III normal: BO
stage III abnormal: ? PI
add pancreatic enzyme,
stage IV normal: PI