How to assess regional and whole gut transit time with wireless motility capsule

Assessment of transit through the gastrointestinal tract provides useful information regarding gut physiology and pathophysiology. Although several methods are available, each has distinct advantages and limitations. Recently, an ingestible wireless motility capsule (WMC), similar to capsule video endoscopy, has become available that offers a less-invasive, standardized, radiation-free and office-based test. The capsule has 3 sensors for measurement of pH, pressure and temperature, and collectively the information provided by these sensors is used to measure gastric emptying time, small bowel transit time, colonic transit time and whole gut transit time. Current approved indications for the test include the evaluation of gastric emptying in gastroparesis, colonic transit in constipation and evaluation of generalised dysmotility. Rare capsule retention and malfunction are known limitations and some patients may experience difficulty with swallowing the capsule. The use of WMC has been validated for the assessment of gastrointestinal transit. The normal range for transit time includes the following: gastric emptying (2-5 hours), small bowel transit (2-6 hours), colonic transit (10-59 hours) and whole gut transit (10-73 hours). Besides avoiding the use of multiple endoscopic, radiologic and functional gastrointestinal tests, WMC can provide new diagnoses, leads to a change in management decision and help to direct further focused work-ups in patients with suspected disordered motility. In conclusion, WMC represents a significant advance in the assessment of segmental and whole gut transit and motility, and could prove to be an indispensable diagnostic tool for gastrointestinal physicians worldwide.