PEORIA — A patient at a Peoria doctors' office needed more medical attention than planned, thanks to a handgun that discharged in his jacket pocket.

The bullet struck the man's right buttock, according to a police report.

The incident happened about 8:45 a.m. Monday at OSF HealthCare Illinois Lung & Critical Care Institute, 1001 Main St.

According to the report, the man had just completed his appointment and was receiving paperwork from a nurse. As the man was donning his jacket, the nurse heard a loud pop.

She asked the man what happened, and he said his gun had gone off, the report stated. He then asked her to call an ambulance.

At first, the nurse believed the man was joking, but then she saw blood on the floor, according to the report.

After officers arrived, they found the gun — a .38 Special Cobra Derringer — in the man's jacket pocket.

A typical derringer is a small pistol that holds two bullets. When police retrieved the man's gun, one bullet remained in the chamber.

The man told police he had knocked the gun against something while he was putting on his jacket. He believed the gun wouldn't fire unless it was cocked.

He also told officers he didn't know why he had the gun in his pocket, the report stated.

The man was transported to OSF HealthCare Saint Francis Medical Center, where he was treated for his wound.

According to police, the man possessed valid state firearm owners identification and concealed-carry cards. He was cited for disorderly conduct and violation of the concealed-carry act.

The Illinois State Police are expected to review the man's FOID eligibility, the report stated.

The lung institute is located in the Illinois Medical Center.