It is especially important for Americans, whose culture does not teach one to be tolerant of discomfort, to keep in mind that pain is the body's warning that actual damage is being done to tissues. Enemas can do no damage and pose no risk except to that rare individual with weak spots in the colon's wall from cancers. When an enema is momentarily perceived unpleasantly, the correct name for the experience is a sensation, not pain. You may have to work at increasing your tolerance for unpleasant sensations or it will take you a long time to achieve the goal of totally filling the colon with water. Be brave! And relax. A wise philosopher once said that it is a rough Universe in which only the tigers survive--and sometimes they have a hard time. Eventually it will be time to remove the nozzle and evacuate the water. Either a blockage (usually fecal matter, an air bubble, or a tight 'U' turn in the colon, usually at either the splenetic, or hepatic flexures located right below the rib cage) will prevent further inflow (undesirable) or else the bag will completely empty (good!) or the sensation of bursting will no longer be tolerable. Go sit on the toilet and wait until all the water has passed. Then refill the bag and repeat the process. Each time you fill the colon it will allow more water to enter more easily with less unpleasantness. Fasters and cleansers should make at least three attempts at a complete fill-up each time they do an enema session. Water and juice fasters will find that after the first few enemas, it will become very easy to inject the entire half-gallon of water. That is because there is little or no chime entering the colon. After a few days the entire colon will seem (this is incorrect) to be empty except when it is filled with water. This is the point to learn an advanced self-administered enema technique. An average colon empty of new food will usually hold about one gallon of water. That is average. A small colon might only hold 3/4 gallon, a large one might accept a gallon and a half, or even more. You'll need to learn to simultaneously refill the bag while injecting water, so as to achieve a complete irrigation of the whole colon. There are several possible methods. You might try placing a pitcher or half-gallon mason jar of tepid water next to the bag and after the bag has emptied the first time, stand up while holding the tube in the anus, refill the bag and then lie down again and continue filling. You might have an assistant do this for you. You might try hanging the bag from the shower head and direct a slow, continuous dribble of lukewarm water from the shower into the bag while you kneel or lie relaxed in the tub. This way the bag will never empty and you stop filling only when you feel fullness and pressure all the way back to the beginning of the ascending colon. Of course, hanging from a slowly running shower head the bag will probably overflow and you will get splashed and so will the bathroom floor