Barium follow through (SBFT) and Small bowel enema (enteroclysis)
There are now a number of approaches to investigating the small bowel like wireless capsule endoscopy, MRI and CT besides single and double balloon enteroscopy. With the advent of these technologies, the use of barium studies to investigate small bowel has declined.
There are two barium techniques to examine the small bowel: SBFT and enteroclysis
The small bowel meal is a modification of the barium follow through and is performed as a dedicated examination of the small bowel without a prior examination of the upper GIT.
The small bowel meal is performed by getting the patient to ingest 400-600 ml of barium suspension with x-rays taken at 30 minute intervals as it progresses through the jejunum and ileum. The leading edge of the barium normally takes 2-6 hrs to reach the ileocaecal junction.
Discuss the advantages of enteroclysis?
Enteroclysis is more sensitive than SBFT because:
- The contrast is administered at a controlled rate directly in the small bowel bypassing the regulatory action of pylorus.
- The entire small bowel is demonstrated in a distended state allowing better diagnosis. As a result of the dilatation, mild strictures, small sinus tracts and fistulas, and minimal extrinsic compressions can be visualized besides better delineation of skip lesions and the proximal and distal extent of diffuse diseases.
- Once the tube is in place, the examination can be completed in 15-30 minutes, thus reducing patient waiting time.
How is enteroclysis performed?
- Bowel prep is usually needed. This is to ensure that the right colon is empty and the barium can flow easily through the distal ileum and into the caecum.
- A tube is inserted through the nose to reach at least the fourth part of duodenum (this is done radiologically and prokinetic agents may be used to help propel the tube in small bowel)
- The barium suspension can be administered by hand from a syringe or by gravity flow from an enema bag.
- Enteroclysis may be:
- the single-contrast method with a barium suspension alone,
- the double-contrast method using an infusion of air, water, or methyl cellulose following the barium infusion to distend the small bowel. This improves sensitivity further.
- A flow rate of 75 ml/min seems ideal for most examinations, and small bowel transit will be accomplished in 5 – 10 minutes.
- During the infusion of the barium suspension, the examiner performs frequent, intermittent fluoroscopic examination of the small bowel.
Discuss the limitations of SBFT and enteroclysis?
- Barium examinations are not very sensitive and specific for small bowel diseases and result in a considerable number of false negative results.
- A barium examination may also overlook extramural complications such as fistulas, sinuses, and extra intestinal abscesses.
- Radiation exposure