1. Department of Anaesthesiology and Intensive Care, Karolinska University Hospital, Huddinge, S-141 86 Stockholm, Sweden
2. Department for Clinical Science, Intervention and Technology (CLINTEC), Karolinska University Hospital, Huddinge, S-141 86 Stockholm, Sweden
3. Gastrocentrum, Department of Surgery, Karolinska University Hospital, Huddinge, S-141 86 Stockholm, Sweden
4. Centre for Gastrointestinal Disease, Karolinska Institutet, Ersta Hospital, S-11691 Stockholm, Sweden