This leads to undigested lactose sitting in your intestines and fermenting. (ora.organic)
Over time, large amounts of undigested lactose can irritate the lining of the intestines, which can result in small amounts of blood in your baby's stools. (breastmilk.com)
These bacteria feed on carbohydrates, including undigested lactose, in a process called fermentation. (greenvalleylactosefree.com)