The aim of this study was to investigate whether implicit emotional memory could be demonstrated in patients undergoing a colonoscopy with midazolam sedation. It was hypothesised that the distress associated with a noxious non-surgical procedure would facilitate the conditioning of neologisms designed to readily associate with the negative experience of colonoscopy. It was further hypothesised that mood (in particular high levels of anxiety), personality (specifically introverted and neurotic patients) and objectively rated peri-operative behavioural distress (especially high ratings of distress) may increase the likelihood of implicit emotional memory formation. The study design was a prospective randomised pre and post repeated measures double blind trial including comparison between three groups. Measurement took place at three different time points both pre- and post-surgical procedure (i.e. immediately before and after the colonoscopy and up to one week post procedure). Also the group that participants were allocated to was randomised and unknown to both the researcher and the participant. The measures used were the Hospital Anxiety and Depression Scale, the Eysenck Personality Inventory, the Behavioural Distress Scale, free recall as a measure of explicit memory for intra-operative events and skin conductance response change as a measure of implicit emotional memory for intra-operatively presented neologisms. The investigation failed to find any statistically significant evidence for implicit memory of neologisms presented during colonoscopy, as detected by skin conductance response, or any differences between those participants presented with 'emotive' and 'neutral' neologisms. There was also no significant effect of mood. personality or behavioural distress on this hypothesised interaction. A potentially unrepresentative and relatively small sample. plus some limitations of methodology. implementation and interpretation are discussed with reference to other research and literature related to the field of interest. Finally. some suggestions are made concerning the direction of future research.