Although the suppositories inserted through the anus for treatment enter into the digestive system, they do not invalidate fasting because digestion is completed in the small intestine and the suppositories do not have any nutritious properties and they are not regarded as eating or drinking when they enter the body through the anus.

Two situations occur during enema: since water, glucose and some salts are absorbed in the large intestine, fasting is invalidated if a liquid containing nourishment is administered into intestines or if an amount of water enough to invalidate fasting stays in the intestine. However, if the water is not kept in the intestines and if the intestines are cleaned immediately fasting is not invalidated because the water is taken out together with the feces in the intestines and the water absorbed during that period is very little.