Hi and welcome.. so ironic I was just talking to a friend about accutane this morning. So sorry it's affected you and you're now in this situation :-( Anyway I'm a fitness trainer and work with a UK charity on fitness post surgery and have an ileo. On a personal level, I have some boring ongoing obstruction/motility issues so I'm not working out as much as I'd like, but as far as your situation is concerned, I'd say given you were so fit before, you're young and know your body and how to train, I can't see any reason why you eventually can't get back to that and train pretty much how you used to.
But.. like the others have said, you've been through a major surgery not to mention the weight loss, so it's going to take some time and you have to be patient. It could take as much as a year to get back to where you were before. You're 8 weeks out now though, so you should be able to get back in the gym and do some light weights, core work and CV stuff... just listen to your body and do what you feel comfortable with. You've also got more surgery looming, so you need to just do what you can, get a little stronger and be prepared that it could take a while after each procedure to rebuild. Don't put too much pressure on yourself. I know it's frustrating, but just take it steady.
I'm mainly a runner and found that the muscle loss, postural changes and imbalances due to surgery, multiple bed rests and just changes in the way I walk, sit, sleep, stand etc affected my running hugely and I was being plagued with niggles and knee injuries. The key seems to be developing good core stability first and that should also prevent parastomal hernias.
There is a heap of research that people with weak abdominal muscles are more prone to hernia. So work on your abdominals, low back, hips, glutes etc and get strong and balanced. Then progress to building up your weights slowly and gradually, listening to your body and stop if you get pain around your stoma or incision. If you had open surgery, you'll need more time as the abdominals will have had more trauma than with lapro surgery.
This is a useful booklet produced by Dansac. I think someone else posted a separate thread about abdominal exercises last week too.
Like the others have said, keep hydrated and just listen to your body. Good luck.
Sarah - 40 year old mum of 2 boys, runner/triathlete from UK
June 2010 - Emergency partial colectomy for peritonitis/perforated diverticulitis. Temporary ileo, reversed Oct 2010.
Reversal failed due to bowel inertia/dysmotility
July 2011 - End Ileostomy - elective
Ongoing dysmotility/adhesions/issues.. but for the most part much better
Follow my blog - http://bagthatruns.blogspot.com