Ross,
I walk/run 5 miles a day and I also have an ileostomy. Did you have a subtotal colectomy or a total removal? I guess it depends on how sore your back passage is getting and how new your ostomy is. I had a subtotal colectomy so my rectum is still intact.
For most ostomates, the pain diminishes after healing and time. There are several things you can do such as a mini-suppository or micro enema to prevent the build up of mucus. And of course hemorrhoid ointment for a sore bum. I just hate feeling that "Not so fresh" feeling. Depending on how much I'm passing, I've even gone as far as putting a minipad in my shorts just so I don't stain my underwear. It may not sound manly, but it does the job.
I know its a good thing to pass mucus and occassionally some blood. You don't want that building up inside. I had a bad episode once that put me in the hospital for 6 days because for some reason, it wasn't passing and just built up to the size of a softball. Needless to say, when the doctor saw me, he thought I was dying. After a couple of days on morphine, my rectum relaxed enough to pass all the bad stuff.
Hope this helps. Let me know if you have any other questions.
Bain