The patient should fast approximately 6-8 hours before the examination, i.e. not to eat or drink. Since the commonly used contrast agents are iodine-based (potential allergen), it is important to use preventive allergy medications in allergic patients.
The examination begins by drinking fluid containing the contrast agent. The amount is relatively significant – about two liters of fluid, which should be consumed within 30 to 45 minutes. Subsequently, the patient is intravenously administered a contrast agent and classic computed tomography is performed. The use of two contrast agents (one present in the gastrointestinal tract and the other present in the circulatory system) enables high quality of visualization of the gastrointestinal tract.
The small intestine is traditionally a very poorly examinable organ. The only options, how to perform an examination used to be classic enteroclysis, computed tomography of the abdomen, endoscopic capsule and very exacting double-balloon endoscopy. CT enteroclysis is effective in diagnostics of small intestine tumors, inflammatory changes, intestinal strictures and intestinal fistulas in Crohn's disease.
The problem is a possible allergic reaction after administering the contrast agent. In addition, drinking of the contrast may be followed by slight nausea and mild diarrhea. Because the procedure is accompanied with a certain radiation dose and should not be repeated frequently.
The examination is great in non-invasive visualizing the cavity of small intestine. In addition, it is completely painless.