double-contrast barium enema


double-contrast barium enema

An imaging study performed in two stages—i.e., barium enema followed by injection of effervescent substance to inflate the gastrointestinal tract—to facilitate visualisation of intraluminal lesions or masses.

Barium Enema

Synonym/acronym: Air-contrast barium enema, double-contrast barium enema, lower GI series, BE.

Common use

To assist in diagnosing bowel disease in the colon such as tumors and polyps.

Area of application

Colon.

Contrast

Barium sulfate, air, iodine mixture.

Description

This radiological examination of the colon, distal small bowel, and occasionally the appendix follows instillation of barium (single contrast study) using a rectal tube inserted into the rectum or an existing ostomy; the patient retains the contrast while a series of images are obtained. Visualization can be improved by draining the barium and using air contrast (double contrast study). Some of the barium remains on the surface of the colon wall, allowing for greater detail in the images. A combination of x-ray and fluoroscopic techniques are used to complete the study. This test is especially useful in the evaluation of patients experiencing lower abdominal pain, changes in bowel habits, or the passage of stools containing blood or mucus, and for visualizing polyps, diverticula, and tumors. A barium enema may be therapeutic by reducing an obstruction caused by intussusception, or telescoping of the small intestine into the large intestine; this is a condition that most commonly affects children.

This procedure is contraindicated for

  • high alertPatients who are pregnant or suspected of being pregnant, unless the potential benefits of a procedure using radiation far outweigh the risk of radiation exposure to the fetus and mother.
  • high alertPatients with suspected perforation of the colon should receive a water-soluble iodinated contrast medium, such as Gastrografin, to prevent barium from spilling into the retroperitoneum and causing an inflammatory reaction in the surrounding tissue.
  • high alertPatients with conditions associated with adverse reactions to contrast medium (e.g., asthma, food allergies, or allergy to contrast medium). Although patients are still asked specifically if they have a known allergy to iodine or shellfish, it has been well established that the reaction is not to iodine, in fact an actual iodine allergy would be very problematic because iodine is required for the production of thyroid hormones. In the case of shellfish the reaction is to a muscle protein called tropomyosin; in the case of iodinated contrast medium the reaction is to the noniodinated part of the contrast molecule. Patients with a known hypersensitivity to the medium may benefit from premedication with corticosteroids and diphenhydramine; the use of nonionic contrast or an alternative noncontrast imaging study, if available, may be considered for patients who have severe asthma or who have experienced moderate to severe reactions to ionic contrast medium.
  • high alertUncooperative patients who may not be able to retain the barium for imaging
  • high alertPatients with conditions such as rapid heart rate, intestinal obstruction, megacolon, acute ulcerative colitis, acute diverticulitis, or suspected rupture of the colon; barium or water from the enema may make the condition worse

Indications

  • Determine the cause of rectal bleeding, blood, pus, or mucus in feces
  • Evaluate suspected inflammatory process, congenital anomaly, motility disorder, or structural change
  • Evaluate unexplained weight loss, anemia, or a change in bowel pattern
  • Identify and locate benign or malignant polyps or tumors

Potential diagnosis

Normal findings

  • Normal size, filling, shape, position, and motility of the colon
  • Normal filling of the appendix and terminal ileum

Abnormal findings related to

  • Appendicitis
  • Colorectal cancer
  • Congenital anomalies
  • Crohn’s disease
  • Diverticular disease
  • Fistulas
  • Gastroenteritis
  • Granulomatous colitis
  • Hirschsprung’s disease
  • Intussusception
  • Perforation of the colon
  • Polyps
  • Sarcoma
  • Sigmoid torsion
  • Sigmoid volvulus
  • Stenosis
  • Tumors
  • Ulcerative colitis

Critical findings

    N/A

Interfering factors

  • Factors that may impair clear imaging

    • Gas or feces in the GI tract resulting from inadequate cleansing or failure to restrict food intake before the study.
    • Retained barium from a previous radiological procedure.
    • Metallic objects within the examination field (e.g., jewelry, body rings).
    • Improper adjustment of the radiographic equipment to accommodate obese or thin patients.
    • Incorrect patient positioning, which may produce poor visualization of the area to be examined.
    • Inability of the patient to cooperate or remain still during the procedure because of age, significant pain, or mental status.
    • Spasm of the colon, which can mimic the radiographic signs of cancer. (Note: The use of intravenous glucagon minimizes spasm.)
    • Inability of the patient to tolerate introduction of or retention of barium, air, or both in the bowel.
    • Residual stool in the colon, which can obscure visualization of the bowel wall and can mimic a polyp.
  • Other considerations

    • Barium enema should be performed before an upper gastrointestinal (GI) study or barium swallow to avoid retention of residual barium which may obscure details of interest.
    • The procedure may be terminated if chest pain or severe cardiac arrhythmias occur.
    • Failure to follow dietary restrictions and other pretesting preparations may cause the procedure to be canceled or repeated.
    • Consultation with a health-care provider (HCP) should occur before the procedure for radiation safety concerns regarding younger patients or patients who are lactating. Pediatric & Geriatric Imaging Children and geriatric patients are at risk for receiving a higher radiation dose than necessary if settings are not adjusted for their small size. Pediatric Imaging Information on the Image Gently Campaign can be found at the Alliance for Radiation Safety in Pediatric Imaging (www.pedrad.org/associations/5364/ig/)
    • Risks associated with radiation overexposure can result from frequent x-ray procedures. Personnel in the room with the patient should wear a protective lead apron, stand behind a shield, or leave the area while the examination is being done. Personnel working in the area during the examination should wear badges to record their level of radiation exposure.

Nursing Implications and Procedure

Pretest

  • Identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this procedure can assist in assessing the colon.
  • Obtain a history of the patient’s complaints or clinical symptoms, including a list of known allergens, especially allergies or sensitivities to latex, anesthetics, contrast medium, or sedatives.
  • Obtain a history of the patient’s gastrointestinal system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Verify that this procedure is performed before an upper GI study or barium swallow.
  • Record the date of the last menstrual period and determine the possibility of pregnancy in perimenopausal women.
  • Obtain a list of the patient’s current medications including anticoagulants, aspirin and other salicylates, herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus). Note the last time and dose of medication taken.
  • Note that if iodinated contrast medium (e.g., Gastrografin) is scheduled to be used in patients receiving metformin (Glucophage) for non–insulin-dependent (type 2) diabetes, the drug should be discontinued on the day of the test and continue to be withheld for 48 hr after the test. Iodinated contrast can temporarily impair kidney function, and failure to withhold metformin may indirectly result in drug-induced lactic acidosis, a dangerous and sometimes fatal side effect of metformin (related to renal impairment that does not support sufficient excretion of metformin).
  • Review the procedure with the patient. Address concerns about pain and explain that there may be moments of discomfort and some pain experienced during the test. Inform the patient that the procedure is performed in a radiology department, by an HCP specializing in this procedure, with support staff, and takes approximately 30 min. Pediatric Considerations Preparing children for a barium enema depends on the age of the child. Encourage parents to be truthful about unpleasant sensations (cramping, pressure, fullness) the child may experience during the procedure and to use words that they know their child will understand. Toddlers and preschool-age children have a very short attention span, so the best time to talk about the test is right before the procedure. The child should be assured that he or she will be allowed to bring a favorite comfort item into the examination room, and if appropriate, that a parent will be with them during the procedure. Explain that there will be monitors in the room and they will be able to watch their procedure along with their health-care team.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Instruct the patient to eat a low-residue diet for several days before the procedure and to consume only clear liquids the evening before the test. The patient should fast and restrict fluids for 8 hr prior to the procedure. Protocols may vary among facilities. Inform the patient that a laxative and cleansing enema may be needed the day before the procedure, with cleansing enemas on the morning of the procedure, depending on the institution’s policy. Pediatric Preps
    ≤2 yearsClear liquid diet 24 hr prior to the procedure; a pediatric Fleet enema [a half or whole suppository (glycerin or Dulcolax) may be ordered instead of the enema] on the evening prior to and morning of the procedure up to 3 h prior to the procedure; NPO for 4 hr before procedure
    3–16 years
    • Low residue diet for 48 hr prior to procedure
    • Clear liquid diet for 24 hr prior to procedure; castor oil or Neoloid, a flavored castor oil, may be ordered the night before the procedure; dose is based either on weight or age—for castor oil, 26–80 pounds give 1 ounce, 81 pounds or greater give 2 ounces; for Neoloid, 2–5 years give 2 teaspoons, 6–8 years give 1 tablespoon, 8–18 years give 2 tablespoons—or Dulcolax oral tablet may be substituted based on age (3–8 years give 1 tablet, age 9 years and older give 2 tablets)
    • Fleet enemas, until fecal return is clear, up to 3 hr prior to procedure
    • NPO for 4 hr prior to procedure
  • Patients with a colostomy will be ordered special preparations and colostomy irrigation.
  • Instruct the patient to remove all metallic objects from the area of the procedure as the metal may impair clear imaging.

Intratest

  • Potential complications:
  • Complications include allergic reaction (related to contrast reaction), abdominal discomfort and cramping (related to retention of barium), peritonitis (related to leakage of barium into the peritoneal cavity, perforation of the colon or hemorrhage, resulting from changes in hydrostatic pressure during administration of the enema or manipulations of the tip of the enema tubing during barium administration to patients with a weak colon; a rare complication that may occur in children, immunocompromised patients, or patients whose colon is already weakened by disease), and constipation, fecal impaction, or bowel obstruction (related to dehydration and/or retained barium).

  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
  • Ensure the patient has complied with dietary, fluid, and medication restrictions and pretesting preparations.
  • Ensure the patient has removed all external metallic objects from the area to be examined.
  • Assess for completion of bowel preparation according to the institution’s procedure.
  • Have emergency equipment readily available.
  • Instruct the patient to void prior to the procedure and to change into the gown, robe, and foot coverings provided. Geriatric Considerations Elderly patients present with a variety of concerns when undergoing diagnostic procedures. Level of cooperation and fall risk may be complicated by underlying problems such as visual and hearing impairment, joint and muscle stiffness, physical weakness, mental confusion, and the effects of medications. A fall injury can be avoided by providing assistance getting on and off the x-ray table and on and off the toilet at the end of the exam. Elderly patients are often chronically dehydrated; anticipating the effects of hypovolemia and orthostasis can also help prevent falls.
  • Instruct the patient to cooperate fully and to follow directions. Instruct the patient to remain still throughout the procedure because movement produces unreliable results.
  • Place the patient in the supine position on an examination table and take an initial image.
  • Instruct the patient to lie on his or her left side (Sims’ position). A rectal tube is inserted into the anus and an attached balloon is inflated after it is situated against the anal sphincter. Geriatric and Pediatric Considerations Reduced muscle tone occurs with advanced age, and fully developed muscle tone may not be present in children. Therefore, elderly patients and children may have difficulty holding the barium in the colon while the images are taken. The balloon tip is used to assist with retention of the barium.
  • Barium is instilled into the colon by gravity, and its movement through the colon is observed by fluoroscopy.
  • For patients with a colostomy, an indwelling urinary catheter is inserted into the stoma and barium is administered.
  • Images are taken with the patient in different positions to aid in the diagnosis.
  • If a double-contrast barium enema has been ordered, air is then instilled in the intestine and additional images are taken.
  • After the procedure most of the barium is removed using the rectal tube. The patient is helped to the bathroom to expel residual barium or placed on a bedpan if unable to ambulate.
  • A postevacuation image is taken of the colon to verify expulsion of the barium.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
  • Instruct the patient to resume usual diet, medications, or activity, as directed by the HCP.
  • Instruct the patient to take a mild laxative and increase fluid intake (four 8-oz glasses) to aid in elimination of barium, unless contraindicated. Pediatric Considerations Instruct the parents of pediatric patients to hydrate the child with electrolyte fluid post barium enema. Geriatric Considerations Chronic dehydration can also result in frequent bouts of constipation. Therefore, after the procedure, elderly patients should be encouraged to hydrate with fluids containing electrolytes (e.g., Gatorade, Gatorade low calorie, for diabetics, or Pedialyte) and to use a mild laxative daily until the stool is back to normal color.
  • Carefully monitor the patient for fatigue and fluid and electrolyte imbalance.
  • Instruct the patient that stools will be white or light in color for 2 to 3 days. If the patient is unable to eliminate the barium, or if stools do not return to normal color, the patient should notify the HCP.
  • Advise patients with a colostomy that tap water colostomy irrigation may aid in barium removal.
  • Recognize anxiety related to test results. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Decisions regarding the need for and frequency of occult blood testing, colonoscopy, or other cancer screening procedures should be made after consultation between the patient and HCP. The most current guidelines for colon cancer screening of the general population as well as individuals with increased risk are available from the American Cancer Society (www.cancer.org) and the American College of Gastroenterology (www.gi.org). Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include cancer antigens, colonoscopy, colposcopy, CT abdomen, fecal analysis, MRI abdomen, PET pelvis, and proctosigmoidoscopy.
  • Refer to the Gastrointestinal System table at the end of the book for related tests by body system.