False positive D-xylose test is seen in-a) Ascitesb) Blindloop syndromec) Aspirind) Hepatic failure
## **Core Concept**
The D-xylose test is used to assess the integrity of the small intestine's ability to absorb carbohydrates. D-xylose is a sugar that is absorbed primarily in the small intestine, and its absorption is not dependent on enzymatic digestion. A false positive test result indicates malabsorption, but the cause may not be related to intestinal mucosal damage.
## **Why the Correct Answer is Right**
A false positive D-xylose test result can occur due to several reasons not directly related to small intestinal mucosal damage. **Ascites** can lead to a false positive result because the D-xylose can leak into the ascitic fluid, reducing the amount available for absorption and thus lowering the serum concentration.
## **Why Each Wrong Option is Incorrect**
- **Option B: Blind loop syndrome** - This condition can actually cause a true positive (or rather, indicate a real issue) in a D-xylose test because the overgrowth of bacteria in the blind loop can metabolize D-xylose, reducing its absorption.
- **Option C: Aspirin** - While aspirin can affect various physiological processes, it is not commonly associated with causing a false positive D-xylose absorption test directly.
- **Option D: Hepatic failure** - Hepatic failure might affect the metabolism of D-xylose but is not a classic cause of a false positive result in the context of D-xylose testing for intestinal absorption.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the D-xylose test can be influenced by factors other than intestinal absorption, such as **ascites**, which can sequester D-xylose, leading to falsely low absorption readings.
## **Correct Answer: A. Ascites**