A retrograde pyelogram (RPG) is an imaging test that uses contrast dye in your urinary tract to take a better X-ray image of your urinary system. Your urinary system includes your kidneys, bladder, and everything that’s connected to them.
An RPG is similar to an intravenous pyelography (IVP). An IVP is done by injecting contrast dye into a vein for better X-ray images. An RPG is done by cystoscopy, which involves injecting contrast dye directly into your urinary tract through a thin tube called an endoscope.
RPG is often used to check for urinary tract blockages, such as tumors or stones. Blockages are more likely to show up in your kidneys or ureters, which are the tubes that bring urine from your kidneys into your bladder. Urinary tract blockages can cause urine to collect in your urinary tract, which can lead to complications.
Your doctor might also choose to use an RPG if you have blood in your urine (also called hematuria). RPGs can also help your doctor get a better view of your urinary system before performing surgery.
Before having an RPG done, there are a few things you should do in preparation:
- Fast for a few hours before the procedure. Many doctors will tell you to stop eating and drinking after midnight on the day of the procedure. You may not be able to eat or drink from 4 to 12 hours before the procedure.
- Take a laxative. You may be given an oral laxative or an enema to make sure your digestive system is cleaned out.
- Take some time off work. This is an outpatient procedure, meaning it only takes a few hours. However, your doctor will likely give you general anesthesia to keep you asleep during the procedure. You probably won’t be able to go to work and will need someone to drive you home.
- Stop taking certain medications. Your doctor may tell you to stop taking blood thinners or certain herbal supplements before the test.
Make sure to tell your doctor beforehand if you’re:
- taking any medications or herbal supplements
- pregnant or think you might be pregnant
- allergic to any kind of contrast dye or iodine
- allergic to certain medications, metals, or materials that may be used in the procedure, such as latex or anesthesia.
Before this procedure, you’ll be asked to:
- remove all jewelry and, in some cases, your clothing
- put on a hospital gown (if you’re asked to remove your clothing)
- lie flat on a table with your legs up.
Then, an intravenous (IV) tube will be inserted in a vein in your arm to give you anesthesia.
During the RPG, your doctor or urologist will:
- insert an endoscope into your urethra
- push the endoscope slowly and carefully through your urethra until it reaches your bladder, at this point, your doctor may also insert a catheter into your bladder
- introduce dye into the urinary system
- use a process called dynamic fluoroscopy to take X-rays that can be viewed in real time
- remove the endoscope (and catheter, if used) from your body
After the procedure, you’ll stay in a recovery room until you wake up and your breathing, heart rate, and blood pressure return to normal. Your doctor will monitor your urine for any blood or signs of complications.
Next, you’ll either go to a hospital room or be cleared to go home. Your doctor may prescribe pain medication, such as acetaminophen (Tylenol) to manage any pain or discomfort you might feel when urinating. Don’t take certain pain medications, such as aspirin, that can increase your risk of bleeding.
Your doctor may ask you to watch your urine for blood or other abnormalities for a few days to make sure there are no complications.
Call your doctor right away if you notice any of these symptoms:
- high fever (101°F or higher)
- bleeding or swelling around your urethral opening
- unbearable pain when urinating
- blood in your urine
- trouble urinating
While RPG is a relatively safe procedure, there are a few risks, including:
- radiation exposure from X-rays
- birth defects if you’re pregnant during the procedure
- severe allergic reactions, such as anaphylaxis, to dye or materials used in the procedure
- inflammation throughout your body (sepsis)
- nausea and vomiting
- internal bleeding (hemorrhage)
- a hole in your bladder caused by tools used in the procedure
- urinary tract infection
A retrograde pyelogram is a quick, relatively painless procedure that helps identify abnormalities in your urinary tract. It can also help your doctor do other urinary procedures or surgeries safely.
As with any procedure that involves anesthesia, some risks are involved. Talk to your doctor about your overall health and medical history before getting this procedure done to avoid any long-term complications.