If you Google "running" and then click on the Wikipedia entry this is what you find under "injuries":
"Due to its high-impact nature, there are many injuries associated with running. Common injuries include "runner's knee" (pain in the knee), shin splints, pulled muscles (especially the hamstring), "jogger's nipple" (irritation of the nipple due to friction), twisted ankles, iliotibial band syndrome, plantar fasciitis, runners bladder, and Achilles tendinitis. Stress fractures are also fairly common in runners training at a high volume or intensity."
I laugh at "jogger's nipple" now but I wonder when I'll get it... And I think I may know what runners bladder is. Especially if it's related to "I birthed two huge children and my bladder will never be the same" bladder.
I've heard tales of ultra runner's just peeing their pants when they are in a race because they don't want to ruin their time. So I have to ask myself, "am I that dedicated?" The answer is no. I might however get to the point where I can squat behind a tree but for now I think I'll just take that extra minute or two on my total time if I really have to go.