it is not noticeable if you have your clothes on, you can't even see it through a bathing suit. Different people choose different types of bags but what i wear work this way. You put a flange on yoru stomach, and it hooks there with a sticky wafter and bandaid material, then it has a ring on it, and a bag snaps onto that ring, think tupperware. Then that bag has a hole at the bottom that rolls up and closes with a sort of velcro like stuff. Although much stornger. When i need to empty it, usually about every four or five hours, depending on what i have eaten, i just sit on the toilet, and unroll it and empty the stuff into the toilet, clean the end roll it back up and go.
Other people wear ones that have clips at the bottom, and some people wear ones where you just throw the whole bag away.
The bag can be replaced with a clean one whenever and most people replace the whole setup every 5-7 days, i change mine on sundays and thursdays, i wouldn't have to do it that often, that's just my routine.
IT doesn't smell, it doesnt' show, it doesn't keep you from doing anything. It actually lets you do things you couldn't do when you still had UC, and it's far more convenient that using the batrhoom the regular way, lol.