pain in the butt

pain in the butt (plural pains in the butt)

1. (Canada, US, informal) A nuisance; a source of trouble or annoyance.

   The customers love it, but the employees think the new system is a pain in the butt.

• May be mildly offensive.

• (source of trouble or annoyance): pain in the neck, pain in the rear, pain in the ass, pain in the arse, pain in the bum, pain in the back

• proctalgia
• headache