Persistent postsurgical abdominal pain (PPAP) is a very difficult to treat pain. This pain can persist for months or even years and significantly diminishes quality of life. The exact underlying cause for this pain persistence is still unclear, which makes its treatment still a challenge. The promising analgesic effects of Δ9-THC in previous research, plus the improved bioavailability of Namisol® in comparison with previous Δ9-THC substances form the basis of the present research proposal.