[Chronic diarrhea--value of function tests in diagnosis]

Area of Science:

• Gastroenterology
• Diagnostic Medicine
• Biochemistry

Context:

• Accurate assessment of gastrointestinal absorptive and digestive functions is crucial for diagnosing various conditions.
• Traditional diagnostic methods often involve invasive procedures or have limitations in specificity and accessibility.

Purpose:

• To provide an overview of established and emerging diagnostic tests for evaluating small intestinal absorptive function, ileal function, hypolactasia, small intestinal bacterial overgrowth, and pancreatic exocrine insufficiency.
• To highlight the principles, applications, and acceptance of different diagnostic modalities.

Summary:

• The D-xylose-adsorption test assesses small intestinal absorptive function.
• The Schilling test investigates ileal absorptive function.
• Lactose breath hydrogen testing is standard for hypolactasia diagnosis.
• Breath tests offer noninvasive evaluation for small intestinal bacterial overgrowth.
• Stool pancreatic enzyme measurement is widely accepted for pancreatic function testing, overcoming limitations of intubation tests.

Impact:

• This review aids clinicians in selecting appropriate diagnostic tests for gastrointestinal disorders.
• It emphasizes the shift towards noninvasive and widely accepted diagnostic methods.
• Understanding these tests improves diagnostic accuracy and patient management in gastroenterology.