Rectal ultrasound can be used to evaluate rectal polyps and masses, in particular to evaluate the extent of involvement of the rectal wall and the perirectal tissues. This information helps the surgeon in planning the most effective surgical approach to removal of the lesion. This study can also be used in followup of patients who have had rectal tumors resected, and is also utilized to evaluate for inflammatory and infectious conditions surrounding the rectum.
Anal ultrasound is used to evaluate the anal sphincter musculature in patients with incontinence or constipation, as well as to evaluate inflammatory and infectious conditions affecting the anal canal, such as fistulas.
Preparation For Your Exam
A mini "Fleets" enema is taken just before the examination in order to provide a clean rectal wall through which to scan. No other preparation is necessary.
During the Exam
After changing into hospital garb, you will be escorted into the Ultrasound Examination Room. You will be asked to lie on a table on your left side with your knees bent. A transducer will be carefully inserted into your rectum by the sonographer or radiologist and the scans and images will then be obtained, by moving the probe forward and backward through the anal canal and rectum.
How long will the exam take?
A rectal or anal ultrasound generally takes 5-10 minutes time.
Will it hurt?
The ultrasound transducer is approximately the size of a finger. While there is some brief discomfort as the probe is inserted, most patients find the discomfort is very minimal and of brief duration. For rectal scans, once the probe is past the anal sphincter, a water-filled balloon is inflated to optimize the image quality, but this does not cause any pain or discomfort. For anal ultrasound, the probe remains in the anal canal as the images are obtained, and this is slightly uncomfortable, but this study is generally completed within 2-3 minutes.
After the Exam
Getting Your Results
The results of the transrectal or transanal ultrasound will be available to your doctor on the day following your exam. You may call your doctor to discuss the results.