This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Gastrointestinal System Including Diarrhea, Subject name: Pediatrics
Carbohydrates malabsorption is detected by: 
Select and explain. 
A. Breath hydrogen test, B. Nitrogen breath test, C. Fecal nitrogen, D. Rapid urease test
A: Breath hydrogen test
Answer: A: Breath hydrogen test 
Explanation: Breath hydrogen test: used to identify the specific carbohydrate (lactose, sucrose, fructose, or glucose) that is malabsorbed. Ex: Lactose, if not absorbed in the small intestine, reaches the colon, where it is fermented to sho-chain organic acids, releasing hydrogen that is detected in the lactose breath test Rapid urease test: for H. pylori