The large intestine comes after the small intestine in the digestive tract and measures approximately 1.5m in length. Although there are differences in the large intestine between different organisms, the large intestine is mainly responsible for storing waste, reclaiming water and maintaining the water balance.
By the time the chyme has reached this tube, almost all nutrients have been absorbed by the body and only water and some electrolytes like sodium and chloride are left. As the chyme moves though the large intestine, water is removed, while the chyme is mixed with mucus and bacteria, and becomes feces. It is important to know that the large intestine produces no digestive enzymes and that the chemical digestion is completed in the small intestine before the chyme reaches the large intestine. The pH in the colon varies between 5.5 and 7 (neutral or slightly acidic).
An enema is the cleansing of the colon or large intestine.
It may be that the average colon has this capacity, but that no one except a woman who has just delivered a baby has that much room in the abdomen to allow the colon to expand to its fullest.
This is probably not the best position for expelling water from the colon because of the need for the wide cecum to push the water up hill to the transverse, and then for the transverse to pump it back up its bag to get it to the descending.