X-rays are widely available and relatively cheap to perform compared with other types of imaging, but they are rarely used to diagnose constipation.
Constipation is a common condition that affects about
Doctors often define constipation as having fewer than
- in emergency departments to see if you may need surgery for bowel obstruction
- to assess complications of constipation
- to look for anatomical structural differences that may be causing constipation.
Research from 2020 suggests that X-rays have poor diagnostic accuracy for constipation. Constipation can usually be diagnosed based on your signs and symptoms alone.
Keep reading to learn more about the role of X-rays in diagnosing constipation.
Constipation is particularly common among children. About
Though X-rays don’t have a role in diagnosing functional constipation, they might help rule out other potential causes of constipation, such as bowel obstruction.
According to a
What about in adults?
Most of the research examining whether there’s a benefit in using X-rays to diagnose constipation has been performed on children. In a 2020 study, researchers examined the potential benefits of X-rays for diagnosing constipation in 481 adults in the emergency room.
The researchers found that X-rays offered little value. Small bowel obstruction was identified in a small number of people, but the researchers concluded that a review of medical history and a physical exam should have been enough to rule out constipation.
This test evaluates anal sphincter muscle function. To perform the test, a healthcare professional will insert a thin tube with a balloon tip into your anus.
When the tube is inside, they will inflate the balloon and slowly pull it out. This test measures your anal sphincter’s muscle strength and checks whether your muscles are contracting properly.
Sitz marker study
Doctors sometimes recommend a sitz marker study to measure how quickly stool passes through your body if you have severe chronic constipation.
This test involves swallowing 24 special markers. An abdominal X-ray is performed on day 5. If more than
Does an X-ray show backed-up stool?
Stool buildup appears on an X-ray as soft and clear areas with air pockets. It’s been reported that X-rays correctly diagnose constipation only 84% of the time and only correctly rule out constipation 72% of the time.
X-rays for diagnosing constipation are often performed in the emergency or radiology department of a hospital.
If your X-ray is planned in advance, your doctor may tell you to stop taking medications for constipation, like laxatives, before the test. This is so they can best visualize the stool in your colon.
During the procedure, you can expect something like this:
- You’ll be asked to remove clothing and other objects that may get in the way of the imaging. You may be asked to change into a hospital gown.
- In most cases, you’ll lie on your back on a table.
- You may have other body parts covered with a lead apron to protect them from radiation.
- You’ll be asked to hold still while the X-ray is being performed. The technician will take the X-ray from behind a protective window. The actual X-ray should take only a few seconds.
Learn more about abdominal X-rays.
Abdominal X-rays often provide
If your doctor sees significant stool backup, they may recommend or prescribe treatments like:
- stool softeners
- lubricants such as mineral oil
- osmotic agents such as milk of magnesia
- fiber supplements
- diet changes like eating more fiber or drinking more fluids
If they see signs of bowel obstruction, you may need hospital treatment. A complete blockage often requires emergency surgery.
Here are some frequently asked questions people have about X-rays for constipation.
Can you see constipation on an X-ray?
Doctors can potentially see stool backup on an X-ray. X-rays are generally poor at diagnosing constipation and offer little benefit over a simple review of your medical history and physical exam.
What does impacted stool look like on X-ray?
Impacted stool shows up as semi-clear areas with pockets of air on an X-ray. X-rays are interpreted by doctors called radiologists.
X-rays aren’t routinely recommended for diagnosing constipation. In most cases, doctors can diagnose constipation by analyzing your signs and symptoms alone and performing a physical exam.
Doctors may use X-rays in some situations to rule out atypical structural differences in your gastrointestinal tract or in emergency cases to check for bowel obstruction.