Fistula

• Justus-Liebig-Universitat Giessen — Giessen, Germany
• Krankenhaus Waldfriede — Berlin, Germany
• End-und Dickdarmzentrum Hannover — Hanover, Germany
• Enddarmzentrum Mannheim — Mannheim, Germany

• Renal unit, Ysbyty Gwynedd, North West Wales NHS Trust — Bangor, Gwynedd, United Kingdom

• Department of General Surgery, Jinling Hospital — Nanjing, Jiangsu, China

• Ayman El Nakeeb — Al Mansurah, Mansoura, Egypt

• Seoul National University Hospital — Seoul, South Korea

• University of Iowa General Clinical Research Center — Iowa City, Iowa, United States

• Humanitas Research Hospital — Rozzano, Milan, Italy

• Government Ayurved Hospital — Nagpur, Maharashtra, India

Not specified

• Anand Surgical Hospital — Amravati, Maharashtra, India