Background and Aims: Hydrogen sulfide, a gasotransmitter, can be formed from L-cysteine through enzymatic pathways in the mammalian tissues, and also by sulfate-reducing bacteria in the colonic lumen. It has been reported that intraperitoneal (i.p.) injection of sodium hydrosulfide (NaHS), a donor for hydrogen sulfide, suppresses responses to colorectal distention in rats (Distrutti et al. 2006). In contrast, we have shown that NaHS enhances T-type calcium channel (T-channel)-mediated membrane currents in neuronal model cells, and that intraplantar injection of NaHS produces mechanical hyperalgesia through activation of T-channels in rats (Kawabata et al. 2007). To clarify roles for luminal hydrogen sulfide in colonic nociceptive processing, we thus examined if intracolonic (i.col.) administration of NaHS could cause visceral pain and/or referred hyperalgesia in mice. Methods: Male ddY mice received i.col. administration of NaHS or capsaicin, and visceral nociceptive behavior was observed for 30 min. The mechanical nociceptive sensitivity of the abdomen was then determined by use of von Frey filaments. For immunostaining of phosphorylated ERK (p-ERK), the mice received i.col. NaHS or capsaicin under anesthesia with i.p. urethane at 1.5 g/kg, and, after 5 min, the spinal cord was fixed transcardially with paraformaldehyde solutions. The excised spinal cord was separated into three segments, T13-L1, L2-L4 and L5-S1, and serially sectioned for staining of p-ERK. Results: Like capsaicin, NaHS, administered i.col. at 0.5-5 nmol/mouse, caused visceral pain-like nociceptive behavior followed by development of mechanical abdominal hypersensitivity to stimulation with von Frey filaments. The pro-nociceptive effect of i.col. NaHS as well as capsaicin was also accompanied by increase in the number of p-ERK-positive cells in the superficial layers of the T13-S1 spinal dorsal horn, particularly at T13-L1 levels. The visceral nociception and referred abdominal hyperalgesia caused by i.col. NaHS were blocked by mibefradil, a T-channel blocker, or 5,5’-dithio-bis-(2-nitrobenzoic acid), an oxidant, but not modified by glibenclamide and verapamil, inhibitors of ATP-sensitive potassium channels and L-type calcium channels, respectively. Conclusions: Our study shows that colonic luminal NaHS/hydrogen sulfide causes visceral nociception and referred abdominal hyperalgesia accompanied by excitation of spinal nociceptive neurons in mice, and indicates that the underlying mechanisms involve redox modulation of T-channels.