So far no optimal protocol for bowel preparation prior to Capsule endoscopy has been established. Recently, several studies have shown that bowel preparation with polyethylene glycol significantly reduces both gastric and small bowel transit times. Similarly, visualization of the small intestine and therefore 'diagnostic yield' have both been shown to be improved by both sodium phosphate and polyethylene glycol preparation. A more recent study by Selby et al also demonstrates that the prokinetic agent metoclopramide (which is known to promote emptying of the stomach) reduced both stomach and small bowel transit time, increasing completion rates from 76% to 97%).