Twenty patients were interviewed shortly after colonoscopy, and the adjectives and phrases they used to describe the experience were formed into a 31-item questionnaire, on which each item was rated using a seven-point scale. This questionnaire was completed by 110 similar patients. Principal components analysis of these responses yielded three components: satisfaction, physical discomfort, and emotional distress. This demonstrates that patients' experience of colonoscopy is multi-dimensional; whether or not a patient feels satisfied is unrelated to how distressing or uncomfortable it is. Component-based scale scores were calculated so as to quantify every patient's experience on each dimension. Procedures performed by the most experienced endoscopist were no less uncomfortable than others, but they were less distressing. Female patients experienced more discomfort than males, but were no more distressed or less satisfied. This questionnaire could be useful in any future audit of colonoscopy from the patients' point of view.