An abdominal X-ray is a picture of structures and organs in the belly (abdomen). This includes the stomach, liver, spleen, and large and small intestines. It also includes the diaphragm, which is the muscle that separates the chest and belly areas. Often two X-rays will be taken from different positions. If the test is being done to look for certain problems of the kidneys or bladder, it is often called a KUB (for kidneys, ureters, and bladder).
An abdominal X-ray may be one of the first tests done to find a cause of belly pain, swelling, nausea, or vomiting. And other tests (such as ultrasound, CT scan, MRI, or intravenous pyelography) may be used to look for more specific problems.
Why It Is Done
An abdominal X-ray is done to:
- Look for a cause of pain or swelling in the belly or ongoing nausea and vomiting.
- Find a cause of pain in the lower back on either side of the spine (flank pain). An abdominal X-ray can show the size, shape, and position of the liver, spleen, and kidneys.
- Look for stones in the gallbladder, kidneys, ureters, or bladder.
- Look for air outside of the bowel (intestines).
- Find an object that has been swallowed or put into a body cavity.
- Confirm the proper position of tubes used by your doctor in your treatment, such as a tube to drain the stomach (nasogastric tube), a feeding tube in the stomach, a tube to drain the kidney (nephrostomy tube), a catheter used for dialysis, a shunt to drain fluid from the brain into the stomach (V-P shunt), or other drainage tubes or catheters.
How To Prepare
In general, there's nothing you have to do before this test, unless your doctor tells you to.
How It Is Done
You may be asked to empty your bladder before the test. You may need to take off any jewelry that may be in the way of the X-ray picture, such as if you have a pierced belly button.
You may need to take off all or most of your clothes. You will be given a gown to use during the test.
You will lie on your back on a table. A lead apron may be placed over your lower pelvic area to protect it from the X-ray.
After the X-ray machine is positioned over your belly, you will be asked to hold your breath while the X-ray pictures are taken. You need to lie very still so the pictures are clear.
Often two pictures are taken: one while you are lying down (supine) and the other one while you are standing (erect view). If you are not able to stand, the X-ray may be taken while you lie on your side with your arm over your head.
How long the test takes
An abdominal X-ray takes about 5 to 10 minutes. You will be asked to wait about 5 minutes while the X-rays are developed, in case more pictures need to be taken. In some clinics and hospitals, X-ray pictures can be made right away on a computer screen (digitally).
How It Feels
You won't feel any pain from the X-ray itself. You may find that the positions you need to hold are uncomfortable or painful. This is more likely if you have an injury.
There is always a slight chance of damage to cells or tissue from radiation, including the low levels of radiation used for this test. But the chance of damage from the X-rays is extremely low. It is not a reason to avoid the test.
An abdominal X-ray is not usually done during pregnancy. Often an abdominal ultrasound is done instead.
In an emergency, the results of an abdominal X-ray are ready in a few minutes. Otherwise, a radiologist usually has the official X-ray report ready the next day.
The pictures made by the X-rays show that the stomach, small and large bowel, liver, spleen, kidneys, and bladder are normal in size, shape, and location.
No growths, abnormal amounts of fluid (ascites), or foreign objects are seen. Normal amounts of air and fluid are seen in the intestines. Normal amounts of stool are seen in the large intestine.
A blocked intestine may be seen because a portion of the intestine is larger than usual or areas in the intestine have abnormal amounts of air or fluid in them.
A collection of air inside the belly cavity but outside the intestines (caused by a hole in the stomach or intestines) may be seen.
The walls of the intestines may look abnormal or thick.
The size, shape, or location of the bladder or kidneys may be abnormal. Kidney stones may be seen in the kidney, ureters, bladder, or urethra.
In some cases, gallstones can be seen on an abdominal X-ray.
Abnormal growths, such as large tumors, or ascites may be seen.
A foreign object is seen or a medical device looks abnormal or out of position.