Govert Veldhuijzen

12 Chapter 1 GENERAL INTRODUCTION The explosive development of flexible endoscopy in the 1960s and 1970s brought a new diagnostic modality to the stage equipped to diagnose gastrointestinal diseases, in particular (pre)malignant oesophageal, gastric and colorectal lesions. 1,2 Endoscopy not only serves as a diagnostic tool but also as a therapeutic tool as endoscopic removal of polyps prevents cancer. 3 In particular, endoscopy of the colon, referred to as colonoscopy, has developed as the gold standard to detect and remove neoplastic lesions. As a relevant number of these lesions, such as adenomas, can have a precancerous nature, this practice has clearly shown to reduce colorectal cancer mortality. 4 This led to introduction of large scale polyp surveillance and colon cancer screening programs which enjoys wide support from the population as well as policy makers. 5 The diagnostic accuracy and therapeutic safety of colonoscopy is influenced by several prerequisites. Important is the quality of the endoscopist who performs the colonoscopy. This is expressed in the number of adenomas found per procedure, or the adenoma detection rate (ADR). In 1 out of 4 colonoscopies, the doctor should find an adenoma. 6 To achieve a high ADR one of the key requirements is optimal bowel preparation, next to adequate training of endoscopists, sufficient endoscope withdrawal time and optimal scheduling of the procedure. 7 Inappropriately cleaned colons result in less detection of relevant lesions. This warrants repeated colonoscopies and shorter surveillance intervals. 8,9 Indeed, a clean colon during colonoscopy reduces cancer morbidity and mortality. 10 There are a number of patient related factors associated with poorly prepared colons such as incomplete laxative regimes, age, gender and comorbid disease. 11 Important reasons not to complete the intake of purgatives for patients are the inability in following instructions, reduced awareness of health behaviour and health illiteracy. 12 Consequently it is paramount to inform and instruct our patients prior to a colonoscopy. 13 Several strategies that bank on optimizing patient education to improve bowel cleanliness have been examined; and I describe these below in more detail. 14,15 The patients journey towards endoscopy deserves optimal patient education on how to follow instructions on bowel preparation. But another pivotal element before endoscopy is that every patient is thoroughly informed about risks and benefits of the procedure (the concept of informed consent). 16 A complete informed consent contains the following elements: the nature of the procedure, its risks, its benefits and its alternatives. The patient should be given adequate time to deliberate and ask