Yes, you can indeed be a adventure mountain biker if you have a stoma. Just because you had an Ostomy doesn't mean that life is over. As a matter of fact, life just goes on and doesn't really change that much for me. Instead of slowing down after I recovered I went the opposite route and sped up into doing extreme sports. I do consider mountain biking ot be a bit extreme. Now granted I live in the midwest and that means that my mountains are not like Colorado. ALthough I have been out there and boy that is insanely fun. So how did having a ostomy work with biking in rough conditions? It was a bit hard to start.
The first thing that helped me was having the right gear. Mountain biking brings out a lot of sweat, and lots of jumps and jolts. It causes a lot of leg and abdominal strain too. So I had trouble with seals and bags working well to start with. I was eventually led to call ostomy store for supplies by a online tutorial and start asking questions. I finally got the courage up to call and I am glad I did. They didn't sell me like I thought they would. Instead I had a great conversation with someone that gave me test products instead. It was a no worries sort of exchange and I more than appreciated it.
When the products arrived I tested them out and biked around my neighborhood. Not everything worked for me but I found a better bag and belt system. It gave me confidence to do a trail and start having some fun again. I got all strapped up and hit the local trail which is actually in the middle of town. I skipped the jumps the first few times, but really got comfortable with my body and the bike going up and down. So I was able to get back to finally doing what I loved and take it up a notch as time moved on. This was a big boost to my life and quality of it. It doesn't seem like much but when you are sitting in surgery thinking all that is good is about to end it sure it nice to get that rush of joy from the trail.
So get out there and have fun. Be active and don't shy away from asking questions and getting help.