Natural Course of Pain Following Surgery Through an Abdominal Incision

In order to be eligible to participate in this study, a subject must meet all of the following criteria: * Adult patients, aged above 18 years * Planned for elective abdominal surgery, e.g. laparotomy or laparoscopy For phase two of this study we will recruit patients from the group that participated in phase 1. Additional inclusion criteria for phase two: * Patients who developed chronic post-operative abdominal pain according to IASP criteria: * Daily pain in the past three months * Pain is continues or intermittent * Pain scores for the worst pain are 4 or higher * Or patients without chronic pain (n=100) who are propensity matched for type of surgery and risk factors for developing chronic pain. Exclusion Criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study: * Mental incompetence * Planned for laparoscopic cholecystectomy * Planned for Caesarean section Additional exclusion criteria for phase two are: * Contra-indications for MRI (without contrast) including: * Severe claustrophobia * Metal splinters in eyes * Cerebral vascular clips * Electronic medical implants * Patients who do not want to be informed about potential incidental findings of MRI-scan