It’s not exactly a glamorous topic, but many people have experienced it at least once: a sudden, sharp bolt of pain in the backside, sometimes described as “lightning bum.” The sensation can be so intense that it stops you in your tracks, yet just as quickly, it disappears, leaving you wondering what on earth just happened.

According to Dr. Hana Patel, a GP at Superdrug Online Doctor, lightning bum describes a sudden, electric shock-like pain in or around the rectum. It usually lasts only a few seconds and is often associated with spasms in the anal or pelvic floor muscles. Although an occasional episode may be harmless, recurring or worsening pain can sometimes point to an underlying condition worth investigating. Several different health issues may contribute to this uncomfortable sensation, and understanding them can help you recognize when medical advice is necessary. Continue below to discover six possible causes and the warning signs you shouldn’t ignore.