µ‐opioid receptor, β‐endorphin, and cannabinoid receptor‐2 are increased in the colonic mucosa of irritable bowel syndrome patients

The gut immune, cannabinoid, and opioid systems constitute an integrated network contributing to visceral sensation and pain modulation. We aimed to assess the expression of the µ-opioid receptor (MOR), its ligand β-endorphin (β-END), and cannabinoid receptor-2 (CB2 ) in patients with irritable bowel syndrome (IBS) and asymptomatic controls (AC) and their correlation with sex and symptom perception.Mucosal biopsies were obtained from the left...