Absolutely! I’ve gone the other way, scuba diving. A healthy pouch can do just about anything. If he’s lost conditioning he probably wants to get back into shape before the trip. Have fun!

I am probably most worried about dehydration.  It is difficult to get used to altitude in the best conditions.   I have heard of people getting blocked and just miserable.  

We were considering trying to go to altitude this summer on the motorcycle to see how he does before we planned the ski trip. 

You certainly have to take precautions against dehydration in any challenging environment, and there’s no harm in “practicing.” The key, IMO, isn’t “how much can I handle?,” but rather “how do I ensure that I’m drinking enough fluid?” So (for example) a camelback might be a good choice if your skiing (or biking) keeps you away from drinking water for extended periods.

thank you

When skiing in the Rockies, I made sure to drink plenty of fluids beforehand and eat a small amount of food. If you are skiing at Vail or similar places, ask about the availability of restroom facilities on the mountain.  For hiking, you can use the woods if the need arises.  Acclamation to high altitudes is no different with a j pouch than it was before he had surgery, but be sure to stay hydrated.

For some reason I had an extreme amount of gas when we skied in higher elevations. Not sure why??

I had altitude sickness at the summit of Pike’s Peak which is over 14,000 feet in altitude. This thread is mainly focused on hydration but as you go higher up the air is thinner with less oxygen and it kind of creeps up on you. I had to descend quickly because I felt rather unwell and I was alone. Don’t forget that altitude in and of itself can have effects on your body and your head. Sometimes people get wrapped up in concern about one possible danger while totally overlooking another. Don’t fall into this trap.