The butt of a joke

Disclaimer: The following entry may lead you to believe that I'm the most unfeeling person alive. Truthfully, I just learned some time ago that it's best to laugh about things, particularly if it's awkward.
So most days, work is rather predictable. I update time cards, and pull folders when jobs are completed. It's my job to send out the invoices, and to take in money. I pay the bills. I administer the profit-sharing and 401k plans. Sometimes I'm just typing and sending proposals on behalf of the main sales staff, but sometimes I'm bidding a project from start to finish. I arrange for deliveries, and I run the errands. I keep the whole office end of the operation up and running, and unfortunately, that also sometimes requires helping our employees when they've been injured.
In the spirit of keeping a delicate situation private, we'll just call the injured employee Bob. It's always sad to hear that an employee got hurt (it actually is a pretty rare occurrence), but Bob is one of my favorites. He's a very sweet guy and really believes in good customer service (though in times past he's promised to do things that were completely impossible). Anyway, I guess Bob hurt himself LAST WEEK on a job, but only told my brother today that he was having a problem. By law, I have to make a first report of injury to our insurers within 24-hours of it being reported to a manager. So while I worked on the paperwork right away, it felt like it was a bit overdue because Bob hadn't said anything.
Anyway, my brother came by to drop off some paperwork and to explain to me the extent of Bob's injuries. Rarely, someone will inhale something (rare because our employees wear dust masks) or get something in their eye (they wear safety goggles as well). I think our last injury was a couple years back when one guy threw his back out unloading insulation from a semi. So when I asked my brother just what was bothering Bob, imagine my surprise when he said, "He hurt his colon."
Now, I don't mean any disrespect to Katie Couric, but I've always just thought there was something funny about colons. It's more the word than the function, but in the spirit of full disclosure, I feel it important to recognize my propensity to laugh when the subject comes up. However, it did seem a little weird to me that Bob would have had a colon problem because of something that happened on the job. Bob speaks English, but it's not his first language and sometimes words elude him. When pressed further, I was able to understand that while crossing some attic trusses for a lay-in application, Bob slipped, and landed very hard on his bottom, with his legs sprawling to either side of the stud on the bottom of the truss. Or, if that sounds confusing, picture yourself on a mountain bike with a very high bar (disproportionately high to your short legs), and slipping forward off the seat. Ouch. Painful for anyone, male or female. But Bob bore the brunt of his injuries on his bottom.
So first of all, you've gotta feel for the guy. However (I'm finding myself having a hard time using the qualifier "but" because of its homonym), it was rather funny trying to describe his problem on paper for the insurance people. Body part injured: "Rectum." I mean, what else can you say? (Actually, my brother suggested many colorful alternatives, but none were remotely appropriate.) Even worse was when I further had to explain the situation to the woman from Builder's Trust. We both knew it was impolite to laugh, but neither of us could help it. She said she'd never dealt with this kind of injury before.
Anyway, Bob did go to the doctor and was given a clean bill of health, so here's hoping this is the last time I have to deal with a bum injury. If I were a less sensitive person, I'd call him up and tell him to get his butt back to work.