A two-year-old child presents with persistent diarrhea, acidic stools and presence of one percent of reducing substance in the fresh stools. What is the most probable diagnosis?: (A) Cystic fibrosis, (B) Lactose intolerance, (C) Rotavirus induced diarrhea, (D) Intestinal tuberculosis
Answer is B. Presence of acidic stools with reducing substance positive, suggests a diagnosis of lactose intolerance.