Digestion depends on a lot of factors. Usually it takes between 12 hours up to 72 hours depending upon the type of food that you take in. the food remains in the stomach for 3 to 5 hours.
For healthy adults its between 24 and 72 hours. After you eat, it takes about six to eight hours for food to pass through your stomach and small intestine. Food then enters your large intestine for further digestion and absorption of water.