Approved by the US Food and Drug Administration in 2001 for diagnosing diseases of the small bowel, capsule endoscopy is the first examination performed when the source of gastrointestinal bleeding is not apparent after a visual examination of the upper intestinal tract or after a colonoscopy.Patients swallow a capsule, roughly the size of a large vitamin pill, that contains a light source, batteries, a small video camera, a radio transmitter and an antenna. The disposable capsule takes about eight hours to move through the digestive system while it transmits images to a recording device worn around the patient’s waist. Impaired visibility caused by residue in the bowel can reduce the diagnostic ability of capsule endoscopy. Although visibility could be improved with bowel preparations or drugs that promote bowel movements, few large comparative studies have evaluated the effectiveness of such methods on small-bowel cleanliness and on the detection of lesions.A recent multicenter study conducted by researchers in France and led by Dr. Marie-George Lapalus of Hôpital Edouard Herriot in Lyon examined the diagnostic efficacy of bowel preparation before capsule endoscopy. In a randomized trial of 127 patients, the scientists found no significant difference in the quality of bowel preparation between patients who drank two doses of oral sodium phosphate solution and fasted for 3 h and those who simply fasted for 8 h before the procedure. No differences were found in gastric or small-bowel transit time or in the detection of lesions.Sixteen investigators independently examined the quality of the images taken with a Given Imaging Ltd. PillCam SB capsule at five locations in the small bowel. Because there was no standardized scale for grading bowel cleanliness, they developed their own scoring method. The researchers evaluated bowel cleanliness and visibility using two scoring systems that assessed the presence of bubbles, liquid and the rate of visibility.Despite a few study limitations, including subjective evaluation of bowel cleanliness using a nonstandardized scoring system and limited statistical power caused by too few participants, the scientists concluded that preparation using oral sodium phosphate cannot be recommended for capsule endoscopy in patients with hidden gastrointestinal bleeding.Gastrointestinal Endoscopy, June 2008, pp. 1091-1096.