The intestines are a tissue from your body.
It would be the perimeter of one tennis court
it goes down
at the intestines
The abdominal cavity
Cellulose is roughage which scrapes sticky residues off the walls of your intestines so the body can eliminate them. Think of it as nature's scouring pad for humans internally.
The intestines belong to the Digestive Tract (or Digestive System.) Fact: Stretched from end to end, the human intestines would stretch a mile, literally!
stomach
intestines
in the intestines
Intestines
Stomach -> Small Intestines -> Large Intestines -> Through Anus and out of the body