Which of the following is suitable test performed for diagnosis of Intestinal malabsorption?
a) D-Xylose Test
b) Stool fat estimation
c) BT-PABA test
d) Hydrogen breath test
EXPLN:-
D Xylose test, Stool fat estimation and Hydrogen breath test are tests for
Intestinal malabsorption.
Fat digestion and absorption being more complex…it is the first to be disturbed in
generalised malabsorption.So Stool fat estimation is the best answer
Tests for fat malabsorption
1.Faecal or stool fat estimation. Most sensitive test for fat malabsorption, but considered
absolete nowadays.Not done routinely in clinical laboratory.
2.14C-Triolein or 13C breath test-Test for fat malabsorption
Tests for Carbohydrate malabsorption
1.D-Xylose test-Test for monosacchride absorption
D-Xylose absorbed from jejunum,hence this is a test for jejunal malabsorption.
But it is test for
- Intestinal Carbohydrate malabsorption.
- bacterial overgrowth in intestine .
- Also it can be due to Disacchridase deficiency
Principle:-Mammalian cells do not produce hydrogen .A breath H2>20ppm indicates
Intestinal malabsorption as undigested carbohydrates like lactose,Sucrose etc causes
bacterial overgrowth in colon.Anaerobic bacteria produces hydrogen.
If Disacchridase deficiency then also disaccharides like lactose reach colon causes
bacterial overgrowth.
This can be a test for bacterial overgrowth also,as bacterial overgrowth need not be
always due to undigested carbohydrates.
Test for Exocrine Pancreas
BT-PABA Test or Bentiromide test
Test for exocrine pancreas.
BT-PABA is a compound cleaved by Chymotrypsin.Excretion of PABA in urine is
monitored