Which test is considered the gold standard for evaluating malabsorption disorders of the intestine?

• A. Serum gastrin level
• B. Urea breath test
• C. Eosinophils
• D. Stool fecal fat

Answer: (D)

Fat malabsorption is best assessed by measuring how much fat is lost in the stool, because that directly reflects the intestine’s ability to digest and absorb dietary fat. The definitive test uses a quantitative 72-hour stool fat collection while the patient consumes a defined amount of dietary fat; if the fecal fat excreted exceeds about 7 g per day, fat malabsorption is indicated. This approach captures the end result of multiple potential problems—pancreatic insufficiency, mucosal disease like celiac or Crohn’s, etc.—and provides a clear, objective measure of fat absorption. Other options don’t address fat absorption specifically: serum gastrin looks at acid regulation, the urea breath test screens for H. pylori, and eosinophils are a nonspecific inflammatory marker—none quantify fat absorption directly.