The three main functions of the human digestive system are to break food down into chyme for the body's use, to secrete and absorb nutrients and bodily fluids into the gastrointestinal tract or the blood, and to store and eliminate waste. The digestive system has major parts and accessory parts.
I think it shows intelligence because your brain can see things others can't, meaning they may also be able to think outside the box, which can be a sign of intelligence.
