HF 8070

Getting Ready for a Rectal Ultrasound with Sedation

Read this entire document at least 1 week before your test. A rectal ultrasound (RUS) is an exam done to look at your rectum. It can help to find the depth of rectal cancers and assess nearby tissue. It can also be used to assess problems with the anal sphincter muscles.

How the Rectal Ultrasound Is Done

During the exam, a flexible tube with an ultrasound tip is passed into your rectum.

1 Week Before Test

Arrange Transportation

Due to the sedation medicines, you must have a responsible adult drive you home. It is recommended that you are observed for at least 6 hours after discharge. You may take a cab or bus home; however, you must have a responsible adult with you other than the driver.

Health Changes

Please tell us about any major health changes, illnesses, or recent hospital stays you have had since you scheduled your test. If at any time you have symptoms of illness (cough, stuffy nose, sore throat, fever, body aches, chills), please call the procedure center to reschedule your test. You should not have this test while ill.

Blood Thinners and Diabetes Medicines

You must call the doctor who prescribes this medicine to see if you need to stop or adjust your medicine before your test. That doctor will tell you how to safely do this.

The UW Digestive Health Center suggests talking to your doctor using the table below. That doctor should give you the final advice on stopping these medicines.

Ask your doctor about your bleeding risk with this test. If your doctor feels your bleeding risk is low, they will likely have you follow the schedule below to stop your blood thinning medicines. If your doctor feels your bleeding risk is high, they may have you follow a different timeline.

The list below has common blood thinning medicines. It does not include all blood thinning medicines.

Blood Thinners

If your doctor tells you not to stop your medicine, please call the GI Procedure Center at (608) 263-8094, as this may affect your procedure.

Iron, Multivitamins with Iron and Fish Oil

Stop taking these 5 days before your test. (You do not need to contact your doctor first).

What to Bring

If you use CPAP or BiPAP for sleep apnea, please bring it with you. We will need it to safely sedate you.

Bowel Prep

Follow your bowel prep instructions in Health Facts for You #6257.

Test Day


  • No food

  • Stay on only clear liquids (no red or purple)

  • Stop drinking everything, even water, 4 hours before you arrive.


Do not use liquid antacids. Take your normal medicines with a small sip of clear liquid up to 1 hour before you arrive. Follow your provider’s directions for your diabetes or blood thinning medicines.

Before the Test

  • Follow the arrival and registration instructions in your cover letter.

  • If you are running late, call us at (608) 263-8094. If you are over 30 minutes late, we may have to cancel and reschedule. We do our best to stay on time.

  • A nurse will review your health history, take your vital signs and attach a heart monitor.

  • A nurse will place an IV and give you medicines to help you relax and keep you comfortable.

  • The test will take about 1 hour.

After the Test

  • Your doctor will review the results and give you a report. We strongly suggest that you have your driver in the room with you to hear the results.

  • You will go to our recovery room for about 1 hour. Your driver may sit with you there.

  • Once awake, you may be given something to drink.

  • Spend the day resting at home. You cannot drive or return to work. You can return to your normal routine the next day.

  • Do not drink alcohol.

  • You may have some gas pains from the air used to distend your stomach. If you belch, this will help.

Who to Call

GI Procedure Center

7:00 am to 5:00 pm

(608) 263-8094

After clinic hours, this number will give you the paging operator. Ask for the Gastroenterology (GI) doctor on call. Leave your name and phone number with the area code. The doctor will call you back.

The toll-free number is 1-800-323-8942.

If you need to cancel your appointment, please let us know at least 5 days in advance.