Tapentadol has been shown effective in models of acute, osteoarthritic, neuropathic and cancer-induced bone pain. There is now an increasing use of tapentadol in postoperative pain treatment in Norwegian hospitals. However, there is a lack of broad-based evidence for the use of tapentadol in the post-surgical setting. So far, to our study group's knowledge, there are only published studies on postoperative pain treatment after orthopedic and dental surgery, but none related to visceral pain. Most studies have so far been initiated by the industry. The standard treatment today, oxycodone, on the other hand is shown in several studies to have a preferable analgesic effect on pain of visceral origin compared to morphine.