What is opaque enema
The barium enema is a radiological examination of the large intestine (colon, sigma and rectum). In order to make this region visible, it is necessary to introduce a suitable contrast agent via the anus through the rectum. The patient, for his part, must carefully respect some indications both during the examination and in the three days preceding it.
Why it runs
The barium enema is a medical procedure performed to examine and diagnose the problems of the large intestine. Its applications, in part limited by the advent of colonoscopy, range from the investigation of particular symptoms (rectal bleeding, chronic diarrhea, alterations of the head, abdominal pain), to the diagnosis of diseases or specific alterations, such as stenosis, intestinal obstructions, polyposis, alterations in the motility of viscera, diverticulosis and colon cancer. Compared to barium enema, colonoscopy has the great advantage of not using ionizing radiation and providing more accurate information, since it can be associated with the removal of a small amount of abnormal tissue (biopsy). However, this is a more invasive examination.
How it is performed
To assess the health of the colon, the radiologist has two main techniques available: the conventional barium enema and the double-contrast barium enema. In both cases it is necessary to introduce a suitable radiopaque contrast agent, generally barium sulphate, by rectal route, since in its absence the radiographic image would not allow any kind of diagnosis to be made.
A well lubricated tube is then inserted into the rectum and once placed, the contrast medium is gradually released. The filling operation can be facilitated by the injection of air into a small balloon placed on the tip of the probe, in order to favor the retention of the barium inside the colon. Everything takes place under radioscopic control by the specialist. Before introducing the probe, a first X-ray is taken to make sure that the colon is well cleaned.
The various filling maneuvers determine a stimulus to evacuation, sometimes intense, which must be controlled up to the go-ahead of the staff. Once the ok is received, the enema can be evacuated and once the bowel is emptied it is necessary to undergo further x-rays. Overall, the examination is generally well tolerated and is only slightly annoying.
In the double contrast barium enema, after evacuation, air is blown into the colon in order to stretch the walls and generate better quality images, capable of showing even very limited alterations. For this reason the double contrast barium enema is generally preferred to the conventional technique.
To facilitate distension of the intestinal viscera and reduce discomfort, they are sometimes administered by injection of antispasmodic drugs.
Whatever procedural technique is adopted, the examination requires the execution of X-rays in different positions to observe the various tracts of the intestine.
Duration
The duration of the barium enema is very variable and depends on the conditions and the collaboration of the patient, as well as on the type of equipment used; on average, the exam takes 20 to 40 minutes.
Prepare for the exam
The diet for the barium enema
The preparation of the patient to barium enema begins a few days before the examination, during which it is recommended to adopt a diet low in waste to eliminate solid and liquid faecal residues that would prevent a correct observation of the colon. Therefore, whole foods, fruit, vegetables, legumes, bread, pasta, sugar, wine, liqueurs and fatty foods should be removed. Grilled meat, boiled fish, broth, rice and boiled eggs are permitted and recommended. The day before the exam, the diet - particularly light and almost exclusively liquid - will be supplemented with appropriate laxative preparations as prescribed by the doctor.
Contraindications
The barium enema is generally not performed during pregnancy, be it certain or suspected, since X-rays can cause damage to the unborn child. If you suffer from heart disease, diabetes, glaucoma or allergies, it is a good idea to tell the staff before the exam. Any medicines taken will have to be communicated at least one week before the appointment.
Although it is not a high-risk procedure, there is, at the moment of air insufflation, the remote possibility of perforation of the intestinal wall, especially in the presence of diverticula. In this case, a closing surgical procedure must be performed. Small bleeding may occur during the examination, especially in patients who have haemorrhoidal plexus varices.
There is no particular prescription or precaution to be observed after performing the barium enema. Some drugs, sometimes administered during the examination, can cause some temporary vision problems; in this case we advise against driving. During the day a sensation of discomfort or fullness may persist, which resolves spontaneously with rest and subsequent evacuations, during which the residual barium is eliminated which gives the faeces a whitish color. Since the barium used during the barium enema can cause constipation, in the following days it is important to take liquids in abundance; if this is not sufficient, the doctor may eventually prescribe a laxative.
The barium enema cannot and must not be performed using barked contrast medium if there is the suspicion of an intestinal perforation and / or hemorrhage, since the barium is not absorbed by the body and should therefore be eliminated by surgery. It is not recommended for use even in the presence of diverticulosis, due to the greater risk of perforation during the execution of the test. In these cases, the barium enema is performed using an iodinated, soluble and resorbable contrast medium.
