Why does corn look the same coming and going? In the bowl and in the bowl?
No, no. It’s: “In the bowl and in the bowl.”
Corn is a 2 parter. Part one, the inside, is a starch… just a sugar that gets metabolised, part 2, the casing, is not digestable. Therefor, it just makes its way through the boweling alley of life. (misspelling intentional)
I don’t know about ‘looks the same’ though. Mine’s usually a little worse for wear after its journey.
From where I’m looking at it, the kernels look whole and intact. I’ve never been curious enough for a closer look.
So, regarding part 2, is the casing that much more different than, say, peas, which I’m not able to recognize as easily hours later?
I’ve seen some extremely recognizable, almost perfectly round, peas in the bowl.
Several factors have to be connected for this to happen.
First you have to swallow the corn or peas more or less whole. Crunching everything with the teeth breaks the hulls and allows the digestive enzymes to go to work.
Second, you need a fairly quick transit time. Normally the churning and acidity of the stomach will break down almost any foods that come in intact. And the pouring on of digestive enzymes in the intestines will turn the mess into a semi-liquid known as chyme.
For this not to happen, the food has to move quickly through the intestines. Many diarrheal conditions will promote rapid transit. I’ll bet that whenever you see whole kernels of corn, the rest of your stool is soft and ragged, indicating that it did not stick in the intestines long enough for even the normal process of the more or less complete elimination of water to take place.
Hey, didn’t your mama tell you to chew your food thoroughly?
I should have called part 2, “number 2” ah well. As Mr. Mapcase points out (and as I failed to) chewing is a big deal as well as digestion rate. Don’t forget, it’s not just diarrheal cases that make you digest rapidly. I was a competitive runner for some time, and would make the visit to the can 3 or 4 times a day. So an athlete who scarfs his food without chewing will also see higher rates of whole corn from the corn hole, as it were.
Also, as an aside, I am left to wonder if corn is semi resistant to the acid in your stomache as well. I say this, because on my Cross Country teams, everyone seemed to know the lovely phrase “there’s always corn,” which referred to the fact that every time someone puked after a meet or race, no matter how long it had been since they ate corn… they still seem to puke up corn.
Interesting; the equivalent here in the UK is diced carrots, which I’ve been told is bits of the stomach lining (unless it actually is diced carrots that were eaten earlier)
I’ve thought about this also. I noticed the corn-shit. The last few times eating it on the cob, I made sure to chew every damn kernal before swallowing the bite. Next day I still was treated to a vision of what I ate. 
Side question. If it’s the hull that’s undigestable, why the hell don’t I see it when I eat a bowl of popcorn? What’s so different?
Well, the colour, for a start; the skins of popcorn kernels are more of a sort of tan colour, which blends in with the… umm… background. Plus it probably makes a difference that popcorn is a very different composition to corn eaten straight off the cob.
As long as we’re on the sunject, I have a related, yet totally disgusting story to share.
We did some major renovations on our house. Being cheap (and stupid), we opted to remain in the house during construction, and moved to the basement, as it was finished and had a functioning toilet and shower.
midway through the project, it rained. Hard. Hard and long. It rained so much that the storm drain system was overwhelmed and (through some mechanism I still don’t understand) spilled over into the towns sewer system.
The result was a geyser of raw sewage erupting from our basement toilet into our temporary living quarters.
When we finally got things under control by stuffing some wadded-up towels into the toilet (propped in place with a pole wedged against the ceiling), I sent the family to a hotel for the night while I took over mop-up detail.
The sump pump got rid of the bulk of the 6 inches of flooding, and I went at the remainder with a wet-vac. However, after some time, I realized that it was no longer pulling up any more water. I stopped it and took a look at the business end of the wand.
It was completely plugged-up with corn kernels.
I had not eaten corn in several weeks.
It was the lowest point of my entire life.
Some of God’s creatures (rodents, etc) pratice coprophagia to optimize digestion. ewwww :cþ
I will attempt to write through the laughter/dry heaving reaction to bizzwire 's story.
I have often noticed popcorn husks, and each time I’m thankful that I come away with no scratches. The little suckers are quite well camouflaged, but with a little diligence, you’ll see em.
Now get back in there and find yourself a winner!
I have a lot of pressure on me at the moment. Thanks, Bizzwire, for pointing out to me that, as temporarily unhappy as I am, my situation could sure be a lot more unpleasant. 
By amazing coincidence, I myself had been wondering about this same corn question just last week (though not wondering enough to try to dig up an answer.) How nice to find that I’m in tune with other Straight Dopesters.
And I am amazed to find that all of the above posters managed to word things such that they avoided disgusting me and spoiling my snacking in front of the computer screen. Thanks.