Barium enema
Discuss the indications of barium enema?
The indications for barium enema are the same as for colonoscopy. The role of barium enema has declined since the availability of CT colonography (CTC). CTC is more sensitive for the detection of polyps and cancer than barium enema and has the added advantage of characterizing extra colonic structures.
Discuss single-contrast barium enema (SCBE) and double contrast study barium enema (DCBE)?
There are two types of barium enemas:
- Single contrast barium enema uses barium to highlight your large intestine.
- Double contrast barium enema uses barium, but also delivers air into the colon to expand it. This allows for even better images.
DCBE is more sensitive than SCBE for detecting colorectal lesions. However, elderly and debilitated patients may be difficult to examine by the double-contrast method because of the need for more frequent movements with double contrast study. Also, detection of small colonic polyps under 1 cm in size is less crucial in elderly patients
Discuss the technique of barium enema?
- Bowel prep as for colonoscopy
- The patient lay down on back (or left lat position) on the x-ray table
- An enema tube is inserted in the rectum.
- Routine distention of the retention balloon at the tip of the enema tube is not necessary. Encouraging patients to retain the air and barium is usually sufficient. Retention balloons are inflated only in patients who are expelling air and barium from the anal canal and only after a normal distal rectum is demonstrated fluoroscopically.
- The enema tube is connected to a bag that holds the liquid barium sulphate (fine, white, odourless and non-toxic).
- The patient is turned in various positions to facilitate passage of the barium through the colon.
- A large enough volume of barium is required to coat the colon. If about one-third of the luminal diameter of distended colon is filled with barium, then enough barium has been instilled to coat the colon.
- Room air (or CO2) is gently and intermittently insufflated into the colon for DCBE
- For DCBE, the patient may be rolled 360° anywhere from one to four times, usually in partial turns. If a patient is elderly or feeble and has difficulty turning, the study should be converted to a SCBE examination. Most patients can accomplish two to three complete turns on the fluoroscopy table, which is sufficient for adequate colonic coating.
- The enema tube tip may be removed after an adequate amount of air and barium has reached the right side of the colon.
- A barium enema and the process of taking X-ray images of the bowel takes around 15 to 30 minutes to complete.
Discuss the efficacy of barium enema?
In experienced hands, the detection of cancer using DCBE techniques in symptomatic patients shows a sensitivity of 90.2% and specificity of 99.5% (Connolly et al 2002). Large polyp detection is also good with a sensitivity of 82.7% compared to colonoscopy which has detection rates of 89.9% (OTT 2000)
Discuss the complications of barium enema?
Bowel perforation 0.02-0.04% (Williams SR 1991)
Abdominal discomfort and bloating
