Continence during activity is a very individual thing. But, mostly it is a matter of time and patience while the pouch adapts and he gets used to what his own personal tolerances are. The hardest thing, for me, was being patient, as it can take a year or more before you get to your best reliable function. He will learn what to eat and drink to improve continence and whether he needs bowel slowers long term. There have been a great many here who resumed very active sporting lives. The main thing is, you just can’t know for sure until you are there. As you know by now, everything surrounding IBD is unpredictable. But, being young is a plus!
Jan