The Troubled Colon

I have a friend (it's possible!) who is diagnosed with an infected colon. His colon seems to be a haven of bacteria at the moment, and the result is pain 24/7. Personally, I can't imagine pain originating from my colon, so I can't "feel his pain," but I do pity his position.

My question: isn't the colon pretty resilient? I mean, the colon deals with, quite literally, a lot of shit day in day out, and you'd think that bacteria laden "material" would strengthen the colon. After all that exposure the colon, one would think, should be invincible to foreign bacteria. But, today, a valuable lesson has been learned: colon's are vulnerable, and don't you dare hope otherwise. I think Howie Day said it best: "even the best [colons] fall down sometime." How true.... how true.