• Colon
• afferent
• human
• pain
• colorectal physiology
• neurophysiology
• sensory neurones

The gastrointestinal tract receives an extensive sensory innervation, crucial both for reflex control and perception of abdominal discomfort and pain. Our understanding of sensory signalling is based almost exclusively on animal studies.1 The paper by Peiris et al (in press) described recording of afferent impulse traffic from segments of the human bowel.2 Such recordings have enormous potential; first, from the perspective of understanding the stimulus transduction processes that operate in human gastrointestinal (GI) sensory endings; and second, enable the pharmacological screening of novel visceral analgesics. The need for the latter arises from the apparent lack of translation from animal models to humans with a number of novel drugs failing in the clinic despite good mechanistic data from animals (eg, Houghton et al3). This has motivated our efforts to record from human GI afferents and here we describe a methodology that shares some similarity with that described by Peiris et al but also some notable differences.

Peiris et al focused on ‘normal’ tissue but the potential is evident for investigation of the mechanisms that give rise to hypersensitivity arising from inflammation. In this respect ‘normal’ refers to tissue from hemicolectomy patients in which normal tissue is available at a distance …