Congrats, Mark, on your 5k! It's good to see that you haven't let the Crohn's hold you back!
I guess I would classify myself as a runner. In the past I have run a few half marathons and more recently, a few triathalons (a local triathalon that swaps a 6 mile canoe trip for the swimming...I'm not sure how I would fare with swimming). I was training for a full marathon four years ago when a full blown flare erupted 5 weeks before the event (I was devastated) and I have not been able to get back up to that level since. I guess my best advice would be what I learned from by marathon training experience: Be very realistic and flexible with your running goals. I used to feel like I had to follow a very strict running schedule and if I failed to do a run, I felt very disappointed in myself. I have since come to terms with the fact that there are always going to be times that I can't do what I would like to and I just have to be happy that I can run at all. Some day maybe I'll do a marathon, but if not, no biggie. The real reason I run is because of how it makes me feel mentally on a daily basis. I know how hard it can be to get back on track when you are sidelined with a flare. On those days, I tell myself that I am just going to put my shoes on and get out the door and if I only walk for 5 minutes, then that's what my body was willing to give me for that day...but I always feel better than not trying at all. More often than not, I find that once I am out there I can do a lot more than I thought.
Also on those days, I try and stay close to home or run a 1 mile loop around a lake by my house where there is a bathroom. That way I am not stranded too far from home with no place to go when the need hits. I have had that happen too many times and it has been a nightmare to say the least.
Final tip is to buy some Calmoseptime. I have had times when I come home and my underwear is literally full of blood from my sore and chafed behind (sorry to be so graphic, but it's true). Then I learned from others on the forum about Calmoseptine and it has been a god send. I put it on before I go out and have very little problems with discomfort.
I hope that you continue to run. Quite honestly, it has been the main therapy that helps me get through this ugly disease. It also gives me the feeling that I am not letting this disease get the best of me. Not to make it sound like it hasn't affected me at all. I will sometimes go weeks without running, and that can be a bummer (no pun intended!). But I know that i will get back up and get out there as soon as I can and I will do whatever I can...even if it's a five minute run!
Best of luck to you. Keep us posted on how you are getting along!