Problem: An infant is brought into a doctor's office with chronic diarrhea. The mother indicates the infant has explosive diarrhea whenever she has milk or milk products. The doctor diagnoses lactose intolerance which means the infant cannot digest milk sugar and suggests giving lactase prior to feeding the infant milk or milk products.
a. Explain how lactose intolerance leads to diarrhea.
b. How does the addition of lactase prevent diarrhea?