[1] Washington Univ, Sch Med St Louis, Div Gastroenterol, St Louis, MO 63110 USA
[2] Washington Univ, Sch Med St Louis, Dept Psychiat, St Louis, MO 63110 USA
[3] St Louis Vet Affairs Med Ctr, St Louis, MO 63110 USA
[4] Univ Leuven, Translat Res Ctr Gastrointestinal Disorders, Leuven, Belgium
[5] Rome Fdn Disorders Gut Brain Interact, Raleigh, NC USA
[6] Univ Gothenburg, Inst Med, Gothenburg, Sweden