A small bowel follow through (SBFT) is a diagnostic imaging test that allows physicians to visualize the small intestine, which is the longest section of the digestive tract. This procedure utilizes a specialized type of real-time X-ray technology called fluoroscopy to observe the movement of a contrast material. Patients drink a solution containing barium, a substance that coats the intestinal lining and appears bright white on X-ray images. The SBFT effectively tracks the contrast as it travels from the stomach through the entire length of the small intestine.
Why This Test is Needed
A physician typically orders an SBFT when a patient presents with chronic, unexplained gastrointestinal symptoms that suggest a problem within the small intestine. This test is frequently used to assess unexplained abdominal pain that has persisted over time. It can also help investigate cases of chronic diarrhea or significant, unexplained weight loss where the cause is not readily apparent from other examinations.
The procedure is particularly helpful in identifying structural abnormalities or changes in the intestinal wall. It is a common tool for diagnosing inflammatory bowel diseases, such as Crohn’s disease, by revealing characteristic patterns of inflammation, narrowing, or ulceration. Furthermore, the SBFT can locate mechanical issues, including partial blockages or obstructions, abnormal masses, polyps, or the source of internal bleeding.
Preparation Requirements
To ensure clear images, patients must follow specific preparation guidelines designed to empty the digestive tract. Most protocols require fasting, meaning nothing should be eaten or drunk for at least eight hours before the scheduled appointment. This ensures the stomach and small intestine are relatively empty, allowing the contrast material to coat the lining clearly.
Patients are typically advised to avoid chewing gum or smoking during the fasting period, as these actions can stimulate stomach acids that interfere with imaging. Patients must discuss all current medications with the referring physician beforehand, especially those for diabetes or high blood pressure. While many prescribed medications can be taken with small sips of water, certain drugs may need to be temporarily adjusted or paused.
Steps During the Procedure
The SBFT procedure begins when the patient changes into a hospital gown and is positioned on the X-ray table. A baseline X-ray image is often taken before the contrast agent is administered. The patient then drinks a specified amount of the contrast material, usually a liquid barium sulfate suspension that may resemble a thin, flavored milkshake.
Once the patient finishes drinking the barium, the technologist or radiologist begins taking sequential images. They use the fluoroscope, which projects a continuous, movie-like X-ray image, to watch the contrast move from the stomach into the small intestine. Because the speed of travel varies significantly, the test duration ranges widely from one hour up to five hours.
During this waiting period, the patient may be asked to rest or walk around briefly to encourage the barium to move efficiently. The radiologist periodically takes detailed static X-rays, called spot images, to capture the contrast material at various points. To better visualize the intestinal lining, the radiologist may apply gentle pressure to the abdomen using a gloved hand or a specialized compression paddle.
As the barium approaches the terminal ileum, the last section of the small intestine, the radiologist focuses on this area because it is a common site for certain diseases. The procedure is complete once the contrast has successfully passed into the large intestine, or colon, and a final set of images is captured.
Interpreting the Findings and Aftercare
Immediately following the SBFT, patients should increase their fluid intake over the next 24 to 48 hours. Drinking water helps to flush the remaining barium out of the digestive system and prevents it from hardening, which can lead to constipation. Patients can usually resume their normal diet and activities immediately after leaving the clinic.
It is common for stool to be white or very light-colored for a few days following the procedure because of the passing barium. If constipation persists or if the patient is unable to pass gas after two days, they should contact their physician promptly. The radiologist, a doctor specializing in medical images, will analyze the X-ray images for signs of abnormalities like strictures, ulcers, or masses.
A formal report detailing the findings will be prepared and sent to the referring physician, typically within a few business days. The referring physician will then discuss the results with the patient and determine the next steps, such as initiating treatment or ordering further diagnostic tests. Findings often include areas of narrowing (strictures), abnormal pouches (diverticula), or changes in the speed of intestinal movement.