PTH-039 Assessment of gastrointestinal transit time of a non-digestible solid: can the “old” wireless capsule endoscopy be as useful as the new SmartPill?

Abstract

Introduction Wireless capsule endoscopy (WCE) has been used since 2001 to detect and diagnose disorders of the small intestine. SmartPill, currently only available in the US, is an innovative method used to evaluate gastrointestinal transit. This is a wireless capsule with similar dimension to WCE that uses the indirect measure of pH change to measure gastric emptying time and small bowel transit time. WCE provides pinpoint accuracy for recognising entry into the stomach, passage into the duodenal bulb and time to reach ileo-caecal valve. It seems likely that like SmartPill, WCE could be used to assess motility as well as mucosal appearance. The aim of our study was to assess gastric emptying time (GET) and small bowel transit time (SBTT) in a series of patients undergoing WCE and to compare these with published studies of SmartPill1. Methods Between January 2008 and November 2009, 301 consecutive patients had WCE in our institution; 134 patients had a normal study (59M:75F; mean age 51±17 years). In these individuals, we used WCE to measure GET and SBTT and compared the results with SmartPill data published in healthy individuals. Results In the 134 patients with a normal WCE study, indications for WCE were: iron deficiency anaemia in 73 (54%), suspected inflammatory bowel disease in 30 (23%), abdominal pain and/or diarrhoea in 24 (18%) and suspected small bowel tumour in 10 (5%). Mean GET was 36±37 minutes and mean SBTT was 238±84 min. The capsule failed to reach the ileo-caecal valve in eight patients (6%). The mean GET reported using SmartPill in healthy volunteers has been reported as 92±44 min in subjects swallowing the capsule with water, and when given with a test meal mean GET was 190±54 min and mean SBTT 332±39 min. Conclusion Highly accurate visual cues observed directly with WCE can be used to accurately measure gastric and small bowel transit times for this non-digestible solid. In our series of patient with normal WCE study, mean GET was 36 min and SBTT was 238 min. This differs substantially from recognised SmartPill values. WCE and SmartPill are insoluble and have similar size and shape; the difference in transit time measurements suggests that measurements based on pH change or direct visualisation of visual landmarks differ. The potential to use either of these capsules to assess motility requires further evaluation.