Anal Ultrasound

What is an Anal Ultrasound?
An examination using high-frequency sound waves to create images of tissue layers beneath the surface of the anal canal. A smooth probe the size of a finger is placed in the anus.  This test is used to map out anal fistulas before surgery, and to look for lesions, tears, or scarring in the sphincter muscles.  It is a safe, painless procedure and no radiation is used. It provides additional information about rectal polyps, rectal cancer, perianal infection and sphincter muscle injuries. The examination is performed by a physician who has special training in ultrasound exams with an assistant present who also has special training for this procedure.

Preparation For Ultrasound
The preparation necessary is two enemas thirty minutes apart beginning two hours prior to the procedure. These enemas will empty the rectum. You need to arrive thirty minutes before the scheduled appointment to allow time for registration and to prepare for the exam.

The Examination
The doctor and assistant will explain the exam to you and answer any questions you have. A nurse will ask you about your medical history and your current medications and have you sign a consent form for the procedure. You will be asked to lay on your left side. The doctor will begin by doing a rectal exam.

Depending on the reason for the ultrasound 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. An additional screen is usually available so that you may watch as the doctor carefully examines the area.

The doctor may decide to do a biopsy (taking small pieces of tissue) by using a small needle that passes through the transducer. The doctor is able to accurately locate and biopsy any suspicious areas with the ultrasound transducer. Your doctor may take several biopsies in different areas to ensure an accurate diagnosis. You may have slight discomfort for a short time during the biopsy, and an antibiotic may be prescribed for 24 hours following a biopsy.

After An Ultrasound
Your doctor will explain the findings to you before you leave. If biopsies were taken, these will be sent to the laboratory and you will be told how to obtain the results.

Doctors involved in your care will also receive the results. You will be given instructions to follow at home. If you had a biopsy, you may be given antibiotics. Usually, there are no restrictions on activity.

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