The Department of Health ad in Duluth features a man pulling his pants down slightly to expose the top of his buttocks and reads, "Cover your butt! Get a colonoscopy," WDIO-TV, Duluth, reported Wednesday.
The department placed a white box over the exposed crack a few days later.
Scott Smith, a department public information officer, said some complaints were filed about the advertisement and officials decided to censor it as an "experiment to see if it keeps the conversation going."
Smith said there are a few similar billboards across the state, but the Duluth one is the only one to be censored.
Boston schools pull out free condoms over wrapping complaints
Aaron Carter is still in love with Hilary Duff