MRI Defecography

​​​​​​​​​​​​​​​​​​​​​​​DOWNLOADABLE PDF:    ​ English   |    ​ Spanish   |    ​ Chinese    |    Vietn​amese

What is an MRI defecography scan?

Magnetic resonance imaging (MRI) is a way to take pictures of your internal organs and tissues. It uses radio waves and a strong magnet to provide clear and detailed pictures.

An MRI defecography scan helps us see how well the muscles in your pelvis are working. These muscles control bowel movements and other functions. This scan can help us understand the cause of your symptoms.

MRI will help your healthcare provider decide which treatment is best for your medical condition.

​How does the scan work?

In most MRI scans, we take 2 or more sets of pictures. Each set takes 2 to 15 minutes. Each one shows a cross-section (slice) of your pelvis.

For Your Safety

​​​Health Review

We need to know about certain health conditions before giving you an MRI scan. Please tell us if you: ​
  • Have any problems with your liver or kidneys
  • Need a liver or kidney transplant
  • Are on dialysis
  • Have allergies to any drugs or contrast
  • Have had any surgeries
  • Are pregnant or may be pregnant

Metal Review

We also need to know if you have any metal in or on your body before we give you an MRI scan. The strong MRI magnet will pull on any ferromagnetic object, such as iron and some other metals.

If you have any metal on or in your body, an MRI can harm you. Even small amounts that will not harm your body can distort the MRI picture.

Please tell MRI staff if you have:

  • Aneurysm clips, a heart pacemaker (or artificial heart valve), an implanted port, an infusion catheter (with brand names such as Port-o-cath, Infusaport, or Lifeport), an intrauterine device (IUD), any metal plates, clips, pins, screws, or surgical staples, a prosthetic hip, or any implanted metal object in your body
    • In most cases, surgical staples, clips, plates, pins, and screws are not a risk during MRI if they have been in place for more than 4 to 6 weeks. If there is any question of metal fragments, an X-ray may be done to check for them.
  • Tattoos or permanent eyeliner
  • Medicine patches
  • A bullet or shrapnel in your body
  • Ever worked with metal

Please also remove any other items that might contain metal and affect your MRI pictures. These include:

  • Hairpins
  • Jewelry
  • Glasses, hearing aids, and any removable dental work

What should I expect?

Before Your Scan

  • You will need to hold urine in your bladder for 30 minutes before your scan.
  • Your doctor will talk with you about the scan and answer your questions.
  • Most times, this scan does not require that we use an intravenous (IV) line or inject contrast.
  • You may need to walk to a different area where your MRI scan will be done. This walk will take 2 or 3 minutes.

During the Procedure

  • You will lie on your right side on a sliding table. The MRI technologist will help get you into position.

Females:

  • The doctor or technologist will insert a catheter (thin, plastic tube) into your rectum and inflate a small balloon at the end of the catheter. The balloon will hold the catheter in place.
  • Your doctor will then inject about 200 mL (less than 1 cup) of gel through the catheter into your rectum. The gel will put pressure on your body parts in that area, and that will make different tissues show up better on the MRI.
  • The doctor will then remove the catheter from your rectum.
  • The doctor will insert a 2nd catheter into your vagina, and then inflate a small balloon at the end of it.
  • A small amount of gel (about 30 mL, or 1 ounce) will be injected through this second catheter into your vagina.
  • The doctor will remove the 2nd catheter from your vagina.
  • You may feel some pain or discomfort when the catheters are inserted into your vagina and rectum. Tell your doctor if you are having discomfort.

Males:

  • The doctor or technologist will insert a catheter (thin, plastic tube) into your rectum and inflate a small balloon at the end of the catheter. The balloon will hold the catheter in place.
  • Your doctor will then inject about 200 mL (less than 1 cup) of gel through the catheter into your rectum. The gel will put pressure on your body parts in that area, and that will make different tissues show up better on the MRI. 
  • The doctor will then remove the catheter from your rectum.
  • You may feel some pain or discomfort during the insertion in your rectum. Tell your doctor if you are having discomfort.

After the Injection

  • You will need to wear a diaper during the exam to catch any gel that leaks out. The technologist will help you put it on.
  • The technologist will slide the table inside the MRI unit and then leave the room to take the MRI pictures.
  • You will be able to talk with the technologist at any time through an intercom. The technologist will also give you instructions through the intercom.
  • Based on how many pictures are needed, the scan usually takes 30 to 60 minutes. A very detailed study may take longer.
  • You will need to hold very still while the pictures are being taken.
  • If your MRI was done in a different area, you will need to walk back to Radiology. You will need to keep the diaper on because the gel will leak out. We will give you a hospital gown and pants to wear.

What will I feel during the MRI?

  • MRI is not painful.
  • Some patients may feel confined or uneasy (claustrophobic) when they are inside the MRI unit. Please tell the doctor who referred you for the MRI if you are claustrophobic. Your doctor may give you medicine that will help you relax during your exam.
  • You may notice a warm feeling in the area where the pictures are taken. This is normal. If it bothers you, please tell the technologist.
  • You will hear loud tapping or knocking noises during the scan. We will provide earplugs or music to listen to through headphones to block some of these sounds.

Who interprets the results and how do I get them?

A radiologist skilled in MRI will review and interpret your MRI images. The radiologist will not talk with you about the results, but will send a report to your primary care or referring doctor. This doctor will give you the results.

Questions?

Your questions are important. Call your doctor or health care provider if you have questions or concerns.

  • Imaging Services: 206.598.6200