Weird new hire physical

This was about 28 years ago, but it came to mind because a new employee just had his new-hire physical. A company that I used to work for sent us to a local medical clinic for the usual stuff--hernia, urine test, lifting 50 lbs, etc., but one of the exams was to check for "anal fissures." Why would a workplace check for that? One of my fellow new hires also thought it was odd, but we never found out why they did it.