Postoperative Ileus: Duration and Severity Assessment With the SmartPill®

Postoperative ileus (POI) is a frequent complication after abdominal surgery leading to nausea, vomiting and infectious complications. Bowel dysmotility can last for days and necessitates parenteral nutrition resulting in an prolonged hospital stay and a high economic burden. Until now there is no evidence based therapy of manifest POI because of missing valid surrogate markers demonstrating the severity and resolution of POI. A novel tool to examine gastrointestinal function is the SmartPill®. By measuring pH value, temperature and intraluminal pressure the capsule is able to analyse gastric emptying, small bowel transit, large bowel transit and peristaltic activity. Unfortunately the use of the SmartPill® is not allowed in the first three months after abdominal surgery. Therefore a trial is needed to investigate the behaviour of the SmartPill® during its passage through the human gastrointestinal tract immediately after surgery. The primary endpoint is \- to investigate the safety of the SmartPill® in patients after abdominal surgery. The secondary endpoints are: * is the SmartPill® able to detect the gastrointestinal transit and the peristaltic activity followed by abdominal surgery compared with patients which underwent thoracic/vascular surgery. * is it possible to correlate the measured parameters (delayed gastrointestinal transit, lack of peristalsis) with the clinical signs of POI (nausea, vomiting, prolonged duration until first postoperative defecation). * is the detected peristaltic activity influenced by intravenous applicated prokinetic drugs * is the detected peristaltic activity influenced by physiotherapy Using those endpoints the investigators hope to demonstrate the safety of the SmartPill® after abdominal surgery, to evaluate its ability to analyse severity and length of POI and to examine whether the used prokinetic drugs and postoperative mobilization are able to influence peristaltic activity.