First check that everything is square.
Interior door suddenly now scraping floor.
Be careful not to cut the door too deep or too far.
Can you tell which it is.
A dragging corner makes a door difficult to open and close.
Use sandpaper a belt sander or circular saw to remove the area where the door rubs.
It sounds like perhaps the door frame is leaning in towards the bathroom or perhaps the bathroom floor slopes up a bit.
Houses settle over time which often causes a door to sag inside its frame.
Assuming the hinge screws are tight it may be that the only way to permanently fix the problkem is by rebuilding the door frame and or fix the slope in the floor.
Adjust the top hinge 1 use a screwdriver to tighten the screws in the top hinge on the door and frame.
Over time these screws can work their way loose causing the bottom of the door to drag on.
Sandpaper can be used for small rubbing problems while the belt sander or circular saw are ideal for more extreme door sticking issues.
The dragging door corner can scrape the floor or threshold.