Hot potato, the catheter and bag is often called a closed system. Once attached the day or leg bag should stay attached for up to 7 days. After seven day the leg bag should be changed. For maximum infection control once anything is disconnected from the catheter it should be thrown away. As already said connect the long night bag tube to the leg/ day bag, make sure the valve is in the right position. After surgery I was given enough non reusable night bags so it could be changed every day.
Since having a permanent catheter I have to make my drainable night bags last for seven days.
I always keep my leg bag on my leg, I attach the night bag to the leg bag tube and secure the long tube to my ankle with a strap. After surgery I wore pj bottoms to save any snagging. The advice is that the night bag should be supported from the top, but I have also let it lay of the floor without any issues.
Thanks Chris