My sister, who is 51, has CP. When she was 30 she had colon cancer and has had a colostomy since that time. Because of her limited mobility and spasticity, it took her a long while to adjust to being able to manage the equipment, emptying, etc., but she knew she didn't want to use adult diapers. I think some things to consider are how is the spasticity/flexibility in your hands/arms, how is your balance on your feet, etc. If you use a wheelchair, I think you'd need to consider how close you can get your chair to sinks, toilets, etc. while out in public as well as at home. Although she originally thought she'd want to use irrigation as a method of managing the colostomy, it turned out that she didn't have the mobility to manage this and just ended up making big messes (yes, we can laugh about it... what is the other option, right?). Good luck... surely this isn't an easy decision.
(She has full use of her urinary system, so no advice there.)