Answer by fly52 (13). Depending on ones diet and current weight, the human body will hold anywhere from 5 to 25 pounds of feces. A lot of this is in the form of old, dried feces and mucus that the body couldn't fully break down and dispose of.he amount of poop your body can hold at one time depends on how much you weigh and your diet. Based on those factors you can have anywhere from just a few ounces of poop all the way up to twenty five pounds of poop in your body at any given time. add a comment. +1 vote!