Is the xylose test still a worth-while investigation?

Area of Science:

• Gastroenterology
• Clinical Diagnostics
• Absorption Testing

Background:

• The D-xylose absorption test is a common diagnostic tool for evaluating gastrointestinal function.
• Assessing the test's utility requires comparison with direct measures of intestinal health, such as jejunal morphology.

Purpose of the Study:

• To evaluate the diagnostic accuracy of the D-xylose absorption test.
• To compare D-xylose test results with jejunal morphology and final diagnoses in adult patients with gastrointestinal diseases.

Main Methods:

• Retrospective analysis of 152 adult patients with gastrointestinal diseases.
• Assessment of D-xylose urine excretion rates and serum concentrations.
• Correlation with jejunal biopsy findings and clinical diagnoses.

Main Results:

• Neither urine nor serum D-xylose levels effectively differentiate patients with mucosal lesions from those without.
• The test showed poor separation between patients with specific gut pathology and those with other gastrointestinal issues.
• D-xylose test results can be misleading when jejunal biopsy is feasible.

Conclusions:

• The D-xylose absorption test has limited value in routine practice when jejunal biopsy is readily available.
• The test may serve as a preliminary screening tool for jejunal biopsy referral under strict normal criteria.
• Relying solely on the D-xylose test can lead to misdiagnosis of gastrointestinal conditions.