OPRM1 and colitis: Within the lumbosacral spinal cord, an overall up‐regulation of anti‐nociceptive‐related markers (p < 0.05 for CB1, CB2, and MOR vs. control; Figures 7 and 8) and a down‐regulation of pro‐nociceptive‐related markers (p < 0.05 for TRPV1 and 3 and Ramp1 vs. control; Figures 7 and 8) was detected following DSS‐induced colitis.