Improving bowel preparation for colonoscopy: a literature review

Colonoscopy has long been called the gold standard for investigating the large bowel. The success of colonoscopy as either a diagnostic or therapeutic procedure depends on the quality of the preprocedure bowel preparation. If the bowel is not suitably emptied of faecal matter, poor visualization of the mucosa follows. This can have considerable consequences. The literature shows a diversity of factors affecting bowel preparation. In any individual case, there may be many possible explanations for poor preparation. A small number of studies have consistently found that there is a difference in the quality of bowel preparation between inpatients and outpatients, with inpatients generally having poorer preparation. Most studies have been small-scale, retrospective audits, with all the limitations of that methodology, including possible bias and incomplete or inaccurate records. As inpatient and outpatient populations are likely to be very different in terms of general health, comorbidities, medication and the reason for needing a colonoscopy - the basis for these differences are likely to be complex, multifactorial and many may not be amenable to modification. A few studies have addressed the effectiveness of providing information (written, verbal, or both) to inpatients and/or clinical staff, as a means of improving colonoscopy preparation. Conflicting results have been found and further research is necessary