A lower GI radiography is a fluoroscopic and filmed examination of the large intestine (colon) that allows visualization of the position, filling, and movement of contrast medium through the colon. It can reveal the presence or absence of diseases such as diverticulitis, mass lesions, polyps, colitis, obstruction, or active bleeding. For a barium enema, high-density barium sulfate is instilled into the large intestine through a rectal tube inserted into the colon. The radiologist, with the aid of a fluoroscope, observes the barium as it flows through the large intestine. X-ray images are taken concurrently.
If polyps are suspected, an air contrast colon examination may be performed, which involves utilizing a double-contrast mixture of air and barium that is instilled into the colon under fluoroscopic visualization. This study is not commonly performed and has been replaced by a colonoscopy as the colon examination of choice.
Defecography, also known as dynamic cystoproctography, is a contrast-enhanced study of anus and rectum function during evacuation that may be performed in young patients to evaluate rectoceles, rectal prolapse, or rectal intussusception.
For children or older patients receiving a barium enema
Because a successful examination of the large intestine depends on the ability of the bowel to retain contrast medium during visualization and filming, special techniques are used for infants and young children and the infirm or uncooperative adult patient.
After inserting a small enema tip into the rectum, the infant’s buttocks are gently taped together to prevent leakage of contrast material during the study.
For the older patient, a special retention enema tip may be used. This device resembles a regular enema tip, but it can be inflated, much like an indwelling urinary catheter, after insertion into the rectum. When the examination is done, the retention balloon is deflated and the tip removed.
Barium enema in the presence of a colostomy
See Clinical considerations when barium contrast is used.
Laxatives can be taken.
Suppositories are of no value.
Follow the healthcare provider’s diet orders.
If irrigation is necessary, a preassembled colostomy irrigation kit or a soft, standard-tip indwelling urinary catheter attached to a disposable enema bag may be used.
Advise the patient that an indwelling urinary catheter is used to introduce the barium into the stoma.
The patient should bring additional colostomy supplies to the radiology department for posttest use.
Patients with stomas
Patients with descending or sigmoid colostomies may need a normal saline or tap water irrigation to wash out the barium.
Advise those who normally irrigate their colostomy to wear a disposable pouch for several days until all the barium has passed.
Have the patient lie on their back while a preliminary abdominal x-ray film is obtained; this step may be omitted at some institutions.
Have the patient lie on their side while barium is administered by rectal enema (i.e., through the rectum and up through the sigmoid, descending, transverse, and ascending colon to the ileocecal valve).
Take conventional x-ray images following fluoroscopy, which includes several spot films. After these are completed, the patient is free to expel the barium. After evacuation, another film is made.
Defecography requires the patient to defecate into a specially designed commode while being evaluated fluoroscopically.
Follow guidelines in Chapter 1 for safe, effective, informed intratest care.
Procedural Alert
Pretest preparation is vital for this examination. For a satisfactory examination, the colon must be thoroughly cleansed of fecal matter. Accurate identification of small polyps is possible only with a clean bowel. The presence of stool can also make the search for bleeding sources much more difficult
Pretest Patient Care
Preparation involves a three-step process over a 1- to 2-day period and includes diet restrictions and a bowel cleaning regimen. Follow institutional protocols.
Explain the purpose and procedure of the test. Patients may be apprehensive or embarrassed. If the patient consents, also include a family member in the patient education process if it appears likely that the patient will need assistance with preparation. Explain the need to cooperate to expedite the procedure. Emphasize that the actual time frame when the colon is full is quite brief. Screen female patients for pregnancy status. If positive, advise the radiology department.
Provide written instructions about the following to the patient that include:
Only a clear liquid diet should be taken before testing (according to protocols).
Stool softeners, laxatives, and enemas need to be taken as ordered to ensure bowel cleanliness necessary for optimal visualization.
Fasting from food and fluids should be followed as prescribed before the test. Oral medications should also be temporarily discontinued unless specifically ordered otherwise. Check with the clinician who orders the test.
Refer to barium contrast test precautions.
Follow guidelines in Chapter 1 for safe, effective, informed pretest care.
Clinical Alert
Determine whether the patient is allergic or hypersensitive to barium. Although rare, the presence of this allergy must be communicated to the radiology department so that alternate contrast media can be used.
Determine whether the patient is allergic to latex. Latex products are typically used to administer the contrast agent; alternate materials must be used if the patient is allergic or hypersensitive. Inform the radiology department of any known or suspected latex allergies.
Inform the radiology department if a procedure is to follow a sigmoidoscopy or colonoscopy, particularly if a biopsy was performed. In the case of biopsy, an iodinated contrast agent, rather than barium, is used.
Posttest Patient Care
Review test results; report and record findings. Modify the nursing care plan as needed.
Tell the patient to resume a normal diet and activity. Assist the patient if necessary. A bowel study can be very exhausting. Patients may be weak, thirsty, hungry, and tired. Provide a calm, restful environment to promote return to normal status.
Follow guidelines in Chapter 1 for safe, effective, informed posttest care.
Clinical Alert
Multiple enemas given before the procedure, especially to a person at risk for electrolyte imbalances, could induce a rather rapid hypokalemia. Enema fluid, if not expelled within a reasonable time, can be absorbed through the bowel wall and deposited into the intestinal spaces and eventually within extracellular spaces.
Caution should dictate administration of cathartic drugs or enemas in the presence of acute abdominal pain, active bleeding, ulcerative colitis, or obstruction. Consult with the healthcare provider or radiology department and consider the following points:
Introducing large quantities of water into the bowel of a patient with megacolon should be avoided because of the potential danger of water intoxication. In general, patients with toxic megacolon should not receive enemas.
In the presence of colon obstruction, large volumes of water from enemas may be reabsorbed and impaction may occur.
Rectal obstruction makes it difficult or impossible to give cleansing enemas because the solution will not be able to enter the colon. Consult the healthcare provider or radiology department.
Strong cathartic drugs administered in the presence of obstructive lesions or acute ulcerative colitis can present hazardous or life-threatening situations.
Be aware of complications that can occur when barium sulfate or other contrast media are introduced into the GI tract. For example, barium may aggravate acute ulcerative colitis or cause a progression from partial to complete obstruction. Barium also should not be given as contrast for intestinal studies when a bowel perforation is suspected because leakage of barium through the perforation may cause peritonitis. Iodinated contrast substances should be used if perforation is suspected.
Fasting orders include oral medications except when specified otherwise.
If the patient has diabetes, alert the radiology department and schedule examination for early morning. If a patient with diabetes is taking metformin, special consideration may be necessary. Consult with the radiology department to determine whether this medication regimen must be suspended the day of and several days after the study.
Colonic Transit Time
This examination is performed on patients with suspected colonic motility disorder. The patient must not take any laxatives, enemas, or suppositories before beginning this test or during the 4–7 days it takes to perform this test.
The patient receives several pills that contain radiopaque markers (sitz markers).
A KUB or series of KUBs are performed at fixed times several days later.
The passage of or retention of these markers is noted and recorded.
Retention of a significant portion of markers 5 days after administration is considered abnormal and is evidence of dysmotility or an outlet obstruction.
A poorly cleansed bowel is the most common interfering factor. Fecal matter interferes with accurate and complete visualization. Therefore, it is imperative that proper bowel cleansing be conscientiously carried out, or the procedure may need to be repeated.
Normal
Normal colon position, contour, filling, movement time, and patency