About 4 hours
Most food in our stomach moves down into the intestine in 3 to 6 hours.
Foods that contain fat are digested slower than those @ carbohydrates. Milk has varying amounts of fat...So if it is low fat milk, then 3-4 hours but if it is full fat milk (regular milk is 4% fat) it may take 4-6 hours to leave the stomach. Much of the digestion takes place lower down in the small intestine over 12-18 hours.