Johnson & Johnson or a good generic brand of baby shampoo such as Equate makes a fine, non-toxic, non-irritating, enema soap in my experience. Amount to use is not critical, but a whisky shot glassful (about 3/4 fl.oz.) in 1000 ml clean tap water or bottled purified water works for me. Baby shampoo's excellent lubricating qualities facilitates easy passage of hard stools and disagreeable odors are suppressed as well. Action is prompt and cleansing is thorough without cramping or other side effects.