Anorectal ultrasound is a painless procedure designed to evaluate the anal sphincter muscle. An ultrasound is an examination using high-frequency sound waves to create images of tissue layers beneath the surface. A short ultrasound probe (about the width of a finger) is inserted into the anus and sound waves are bounced off the muscle giving a precise anatomic picture of the muscle. Ultrasound examination involves no radiation and is a very safe procedure. It provides additional information about rectal polyps, rectal cancer, perianal infection, and sphincter muscle injuries The examination takes about 10 minutes to perform.
During the Examination
You will be asked to lie on your left side and the surgeon will begin by doing a rectal exam. Depending on the reason for the exam, an instrument called a proctoscope may be inserted into the rectum. The ultrasound transducer is then inserted either through the proctoscope or by itself. A transducer sends and receives sound waves that are used to create images on the screen. The transducer is passed back and forth over the area of concern to fully examine it. At intervals photographs of the ultrasound image are taken to document the findings.
Your surgeon will explain the findings to you before you leave. Other doctors involved in your care will also receive the results. Ultrasound examinations have no lasting side effects and you can expect to resume all your normal activities after the procedure.