The role of intestinal opioid tone in inflammation-induced visceral hypersensitivity was assessed by colorectal distention.

We found that SCS induced a significant depression of the VMR produced by colorectal distention in both normal rats and those with sensitized colons.

Colonic sensitization with acetic acid increased the VMR to innocuous levels of colorectal distention (30 mm Hg for 10 min).