Intravenous pyelography (IVP), also known as intravenous urography (IVU), is a procedure to X-ray the urinary system. The urinary system includes the kidneys, the ‘ureters’ – tubes that connect the two kidneys to the bladder – and the bladder itself. To make the kidneys and urinary system show up on the X-rays, an injection is given intravenously (into a vein) of a substance that the kidneys take up from the blood stream and pass into the urine. This substance, which is called contrast medium, shows up bright white on the X-ray. By taking several views over a short period, it is possible to check that both of the kidneys and the urinary system is functioning normally.

IVP is usually performed to find out whether renal colic (pain in the back that radiates around the side into the groin) is being caused by renal stones. IVP can also be used to investigate the cause of infection in the urinary system, especially if this is recurrent. Sometimes the procedure may be used to investigate the cause of blood and/or protein in the urine.

Depending on the reason for which it is being performed, IVP may be undertaken as an inpatient (ie with an overnight stay) or outpatient (day case) procedure. It takes place in the radiology (X-ray) department of the hospital. The X-rays are taken with you lying down on a special bed. To be able to give the injection of contrast medium, a ‘drip’ is put into a vein in the back of your hand or in the arm. The first picture is taken before the contrast medium is injected. When the contrast medium is injected by the doctor, you may have the sensation of warmth or flushing all over. This is normal, and no other discomfort is involved. A series of X-rays is taken, usually over a period of less than an hour. At some point you may be asked to go to the toilet to empty your bladder. Occasionally it may be necessary for you to come back to the radiology department for a final X-ray the next day.

IVP does not require any special preparations, such as fasting, before hand. Except in exceptional circumstances, IVP is not carried out on pregnant women because of the risk of the X-rays to the unborn baby. As with all X-rays, a woman should tell her doctor if she knows that she is pregnant or thinks that she might be. You are given a medical gown to wear.

The only serious complication of IVP is an allergic-type reaction to iodine contained in the contrast medium. If this occurs, it usually begins as a difficulty in breathing and does so within minutes of the injection. Reactions to contrast medium are uncommon, but occasionally can be serious, and may require emergency treatment.

If the IVP is performed as an outpatient procedure, the ‘drip’ is removed and you are able to leave the hospital after an hour or two, when the series of pictures has been completed. If you are an inpatient, you will be taken back to the ward to stay overnight.

Apart from drinking plenty of fluids to help clear the contrast medium from the system, there is no particular aftercare following IVP, and side effects after the procedure are very rare.