A barium enema is a test that highlights the lower part of your gastrointestinal system (your large bowel or colon) allowing it to be seen in an X-ray.
What is a barium enema?
The lower part of your gastrointestinal system is known as your large intestine or colon and it consists of four parts – the ascending colon, the transverse colon, the descending colon and the sigmoid colon which joins to your rectum.
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These lower parts of your bowel aren't easy to see on an X-ray so a heavy white fluid (barium) is inserted into your bowel through your rectum (bottom). It coats the inside lining of your bowel making it easier to see various characteristics of the large intestine, eg, tumours, polyps, blockages, pouches and changes in structure. Barium is not radioactive and is not absorbed by your body but is passed out through your rectum. The image below shows the highlighted area on an X-ray.
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Barium enemas are usually carried out in radiology centres by radiologists (a specialist doctor who interprets X-rays) or radiographer (a specialist who operates image machines like X-rays). There will usually be a nurse present.
A barium enema can be unpleasant and uncomfortable but it shouldn’t be painful.
When is a barium enema done?
A barium enema is done to look at your colon to make or confirm a diagnosis. It may be done:
- if you have blood in your stools (poo)
- for changed bowel habits
- for unexplained weight loss
- for unusual bloating or abdominal pain
- to detect growths or polyps
- to diagnose bowel cancer
- for inflammatory conditions of the bowel such as ulcerative colitis or Crohn's disease.
Barium enemas aren't done during pregnancy because the X-rays may harm the baby so let your healthcare team know if you are pregnant or think you could be pregnant. They are also not advised in some situations, eg, for people with a suspected bowel perforation, severe ulcerative colitis or severe abdominal pain.
What do I need to do to prepare for this test?
You should receive instructions from the radiology service before your appointment. Your bowel needs to be completely clean so the area to be examined can be seen clearly. Commonly you will be asked to:
- Eat a light diet for a few days leading up to the test – low fibre foods such as clear soup, white bread, white rice, pasta, peeled potato, cheese, plain crackers. Talk to your healthcare provider if you have diabetes as you may need to follow different dietary instructions in order to manage your glucose levels.
- Take laxative medicine to help empty your bowels. The radiology centre will let you know which medicine to take and how to take it.
- Drink plenty of clear fluids in the 24 hours before the test.
You can bring a support person with you on the day but they won't be able to come in with you while you have your procedure as it involves X-rays.
What will happen on the day of the test?
Before the test
You will be asked to change into a hospital gown and take off all jewellery. There will be private spaces for you to get changed in.
During the test
The barium test usually takes about 45 minutes. You will be asked to lie on a special X-ray table and you may be given a medicine to help relax your muscles.
The radiologist will insert a small, soft tube a few centimetres into your bottom and it will stay there for the duration of your test. The radiology will pass barium through the tube. You may also feel the need to pass a motion, but try to tighten your bottom muscles around the tube. Taking slow, small breaths will also help. You may have some air pumped into your bottom to help expand the bowel.
The radiology team will take several X-rays. As each X-ray is taken, you will be asked to lie still and hold your breath. Once they are done, the tube will be removed from your bottom and the procedure is complete. You can then go to the toilet to empty your bowels.
After the test
It's best to arrange for somebody to drive you home in case you feel unwell after the test. You may need to stay close to a toilet for a while afterwards, so you can expel any remaining barium and air still inside you.
What happens in the days after the test?
In the next few days:
- You can eat and drink as normal – drink plenty of fluids and eat high-fibre foods for the first few days to help stop the barium causing constipation.
- You may have some bloating, wind or stomach cramps.
- Your poo may be whitish in colour for the next few days. This is normal and it’s due to the colour of the barium.
- If you have an inflammatory bowel condition such as ulcerative colitis, barium enema can aggravate this.
- The results of the test will be sent to the healthcare professional who referred you, and they will arrange a time with you to talk through your results.
What are the risks?
A barium enema is considered to be a safe test, but there are a few points to be aware of:
- A very small number of people can be allergic to barium. If you are allergic to other medicines, contract media, iodine or latex you should let your healthcare team know.
- All X-ray examinations involve exposure to radiation in varying amounts. The doses used in medical X-rays are very low and are thought to be very safe.
- Barium enemas have been known to aggravate ulcerative colitis.
- There is a very small risk of putting a hole in the side of the bowel.