[1] Charite, Div Psychosomat Med & Psychotherapy, Dept Med, D-10117 Berlin, Germany
[2] Charite, Div Hepatol Gastroenterol & Endocrinol, Dept Med, D-10117 Berlin, Germany
[3] Univ Calif Los Angeles, Dept Med, CURE Digest Dis Res Ctr, Ctr Neurobiol Stress,Digest Dis Div, Los Angeles, CA 90024 USA
[4] VA Greater Los Angeles Healthcare Syst, Los Angeles, CA USA
[5] Martin Luther Hosp, Dept Med, Berlin, Germany
[6] Martin Luther Hosp, Inst Neurogastroenterol, Berlin, Germany
[7] Robert Koch Inst, D-1000 Berlin, Germany