Sandpaper can be used for small rubbing problems while the belt sander or circular saw are ideal for more extreme door sticking issues.
Interior door suddenly now scraping floor.
Over time these screws can work their way loose causing the bottom of the door to drag on.
First run a piece of paper at the bottom of door to identify where is sticky.
Use a pencil or a label to mark where you need to sand down.
It sounds like perhaps the door frame is leaning in towards the bathroom or perhaps the bathroom floor slopes up a bit.
A dragging corner makes a door difficult to open and close.
Be careful not to cut the door too deep or too far.
Houses settle over time which often causes a door to sag inside its frame.
The dragging door corner can scrape the floor or threshold.
Doors bind and scrape for several reasons but it s frequently due to loose hinges or slight movement in the building which throws door openings slightly out of square.
Use sandpaper a belt sander or circular saw to remove the area where the door rubs.
Can you tell which it is.