Angy,
My colon decided to mutiny, and it almost killed me - I woke up one morning with massive bleeding. They gave me 6 units of blood at the ER, and it stopped bleeding on it's own, about mid-morning. That afternoon, they gave me some go-litely to drink, and then scoped me, but they couldn't locate the source of the bleed.
Later in the day, it started bleeding again, even faster, (they had to put an IV line in my neck, so that they could feed the blood directly into my heart, in order to replace the blood fast enough), while they prepped me for surgery. They tried to locate the bleed again, but couldn't, so they took out the entire colon, in order to save my life.
I now have an ileostomy, (IOW, my ileum feeds directly into a pouch, that I change out, as it fills up), just below my belt line, on my right side. A lot of Crohn's patients end up this way, if their disease is very active, and mostly targets their colon. The colon's main job is to recover water from the fecal stream. All nutrient absorption takes place in the small intestine, so the colon is not necessary for survival, it's just convenient to have.
Tex