WAbdominal examination
WCapsule endoscopy
WCharcot's cholangitis triad
WColonoscopy
WEndoscopy
WEsophageal motility study
WEsophageal pH monitoring
WEsophagogastroduodenoscopy
WFecal occult blood
WLower gastrointestinal series
WRectal examination
WSigmoidoscopy
WSims' position
WStool guaiac test
WUpper gastrointestinal series