The large intestine is mainly used to store feces and waste. It contains anywhere between 10-50% bacteria. The large intestine use that bacteria to break down any proteins that have not been completely digested. It is then eliminated through the anus. The large intestine is wide in diameter but short measuring in at about 5 ft long. Whereas the small intestine is long and narrow and is about 7 ft long. The average human intestine is around 25-28 ft long.