Barium Enema Examination

A barium enema is a rectal injection of barium given to coat the lining of the colon and rectum. The barium enema procedure may additionally use air in the large bowel to give a double contrast technique. A barium enema is now performed less often than in the past because of the increasing use of colonoscopy and other radiological investigations.

• Barium is run into the colon under gravity via a tube inserted into the rectum.
• Buscopan® may be given to minimise spasm.
• Either single or double contrast is used. Double contrast is preferred but single contrast is often considered sufficient in children, when the patient is uncooperative, when gross pathology is being excluded, in the evaluation of obstruction or volvulus and for the reduction of intussusception.

• To assess the anatomy of the large bowel and occasionally the terminal ileum. Abnormalities detected include tumours (benign or malignant), ulcers, diverticulae and thickening of the lining of the colon or rectum.
• A barium enema is not reliable for the diagnosis of rectal pathology.

Indications for barium enema as advised by the Royal College of Radiologists¹

• Suspected small bowel disease (e.g. Crohn's disease); barium small bowel enema (gradually being replaced by CT in adults and ultrasound in children and young women).
• Malabsorption; barium small bowel enema may be indicated, e.g. if diagnosis of coeliac disease uncertain and biopsy is normal or equivocal, and for complications of coeliac disease such as lymphoma. Barium small bowel enema is more accurate than a barium small bowel meal.
• Change of bowel habit to looser stools with or without rectal bleeding persistent for 6 weeks; suspected or possible colorectal neoplasia (colonoscopy is first line investigation but barium enema is an alternative).
• Chronic or recurrent lower gastrointestinal blood loss; only if endoscopy (initial investigation of choice) is not possible.
• Long term follow up of inflammatory bowel disease of colon; barium enema has a limited role after complex surgery and in the evaluation of fistulae. Colonoscopy is more reliable in identifying complications, e.g. dysplasia, stricture and carcinoma.
• Acute large bowel obstruction; water-soluble studies with contrast enema can confirm diagnosis and level of obstruction, and may indicate the likely cause.

Therapeutic uses

• Intussusception:
  • Conservative treatment with barium, air or saline enema is effective in 70-80% of children who present with intussusception unless diagnosis and treatment is delayed.
  • Few complications are reported although recurrence occurs in approximately 1 in 10 patients.²
• Volvulus:
  • Barium enema may be effective in reducing large bowel volvulus in children but resection of the involved segment and primary anastomosis is the definitive treatment.³

• Barium enema is uncomfortable for the patient and requires good patient mobility and cooperation. Should not be requested for frail elderly patients unless there is a clear indication.
• A rectal examination or sigmoidoscopy is essential to avoid missing abnormalities.
• Radiation exposure - relatively low.
• Perforation of colon (rare).
• Barium impaction causing large bowel obstruction (rare).

Prevention of endocarditis

Patients with a prosthetic valve or who have had endocarditis should be given:⁴

• Intravenous amoxicillin and intravenous gentamicin before the enema and then oral amoxicillin six hours later.
• Patients who are penicillin-allergic or who have received more than a single dose of a penicillin in the previous month should be given alternative regimes of intravenous vancomycin and intravenous gentamicin, intravenous teicoplanin and gentamicin, or intravenous clindamycin.

• Allergy to the latex balloon on the tip of enema tube (rare).
• Severe rectal inflammation or recent rectal biopsy (delay for 7 days after a full-thickness biopsy). Patients with active colitis should not have a barium enema.
• Allergy to the latex balloon on the tip of enema tube (rare).
• Severe rectal inflammation. Patients with active colitis should not have a barium enema.
• Acute gastrointestinal bleeding (precludes use of angiography).¹
• Pregnancy: x-rays of the abdomen and pelvis should be avoided.

• Low residue diet for three days prior to the procedure and laxatives 24 hours before.
• Nil by mouth after midnight.
• Bowel washout immediately prior
• Patient lies on side and an enema tube is inserted into the rectum.
• Barium is introduced rectally and radiographs are taken. Air is also then introduced into the rectum for a double contrast barium enema.