Why do we have a large intestine? The stomach and small intestine do most of the work of extracting nutrients from whatever we eat, leaving the (ahem) residue to be stored in the large intestine until we can find a convenient time and place to offload it. That certainly works well in the modern era of indoor plumbing, so yay for that, but what survival advantage did it impart during the millions of years of mammalian evolution to have to carry a load of crap around with us wherever we went?
Water is extracted from whatever passes through it.
To follow up on what Joey P said, the colon removes water from your digestive slurry exiting the small intestines. This is important, for at least a couple of reasons: it saves you from having to intake even more water than we do to stay hydrated, and it reduces the residue from our scat, which presumably is a positive survival trait.
In addition, the large intestines soak up a significant amount of vitamins from the chyme (that slurry I talked about), many of which are the by-product of bacteria in your large intestine attacking the chyme. So it’s not accurate to think that all nutrients from digestion are absorbed by the small intestine.
In addition to the above, the colon contains large amounts of flora which are increasingly recognized as important to health.
The main nutrient absorbed in the colon is vitamin K, which we do get from our diet but most of it is manufactured by colon bacteria. It does lots of other things too.
:smack: ignorance fought, here:D
Thanx. I didn’t even know I missed that week of health class.
It can also make a stylish scarf that is guaranteed to cause a stir, even in the fanciest of restaurants.
Does one leave it attached to the small intestine? I wish to avoid a serious social faux pas whilst dining.
Yeah, get it wrong and you could be in deep… trouble. 
Soylent Green Summer Sausage
So when one gets diarrhea, does that mean the LI isn’t doing its job?
There are small bowel diarrheas (enteritis) and large bowel diarrheas (colitis). Things get broken down further by the mechanism (for example secretory).
Sounds like a bunch of shit to me.
Fashion! This guy gets it, right down to the sublime nuances and details. 
The colon has a vital role in supporting supplement pushers and other woo promoters who make $$$ convincing people that it’s full of toxins and must be “detoxified”. Beware: “death begins in the colon”*. :eek::eek::eek::smack:
Reminds me of the pioneering quack who said one vital purpose of the spine was to support the chiropractor.
*favorite line in the article: “the colon cleanse program is not all roses and sunshine”.
Without your intestines you’d be unable to digest. Then you’d look a bit of a fool, wouldn’t you?
And in pigs, they are good for chitterlings (for certain definitions of “good”).
o/ GUT! Huh! Good god, y'all! What is it good for?! o/
I wonder if ZDoggMD has ever done this as a parody.