<prompt> A 2-year-old child, fed on milk diet, presents with persistent diarrhea, acidic stools pH of stools less than 5.5 on two separate occassions and presence of 1 of reducing substances in the fresh stools. What is the most probable diagnosis: September 2012Cystic fibrosisLactose intoleranceRotavirus induced diarrhoeaIntestinal tuberculosis  <response>: Ans. B i.e. Lactose intolerance 