Finally, I find myself in the bathroom taking the longest hottest shower of my life.
When they try to wean themselves off the pills, they find it nearly impossible, at first, to go to the bathroom normally.
Most likely Galt heard Willie Anschutz rattling the bathroom door, a disruption that doubtless would have tried his concentration.
1780, from bath + room (n.). Originally a room with apparatus for bathing, used 20c. in U.S. as a euphemism for a lavatory and often noted as a word that confused British travelers. To go to the bathroom, euphemism for "relieve oneself; urinate, defecate," from 1920 (in a book for children), but typically used without regard for whether an actual bathroom is involved.