Wireless capsule motility: comparison of the SmartPill GI monitoring system with scintigraphy for measuring whole gut transit.

INTRODUCTION: Assessment of whole gut transit, by radio-opaque markers or scintigraphy, is used to evaluate patients with constipation for slow gastrointestinal transit. Wireless capsule motility, using the SmartPill GI monitoring system, samples and transmits intraluminal pH, pressure, and temperature data from a capsule at regular intervals as it traverses through the gastrointestinal tract; from these, gastric emptying and whole gastrointestinal tract transit can be assessed. The objective of this study was to compare the SmartPill with whole gut transit scintigraphy to determine whether the SmartPill system could serve as a test for measurement of whole gut motility and transit.

METHODS: Ten healthy, asymptomatic subjects underwent simultaneous whole gut scintigraphy and SmartPill assessment of whole gut transit.

RESULTS: All subjects completed the study per protocol and experienced natural passage of the pill. Capsule residence time in the stomach correlated very strongly with percent gastric retention of the Tc-99 radiolabel at 120 min (r = 0.95) and at 240 min (r = 0.73). Small bowel contraction-min(-1) measured by the SmartPill correlated with small bowel transit % (r = 0.69; P = 0.05) and with isotopic colonic geometric center at 24 h after ingestion (r = 0.70, P = 0.024). Capsule transit time correlated with scintigraphic assessment of whole gut transit.

CONCLUSIONS: SmartPill capsule assessment of gastric emptying and whole gut transit compares favorably with that of scintigraphy. Wireless capsule motility shows promise as a useful diagnostic test to evaluate patients for GI transit disorders and to study the effect of prokinetic agents on GI transit.