Poor bowel preparation at colonoscopy may be associated with incomplete colonic examinations, inadequate mucosal visualization, missed lesions, prolonged procedure time, and increased complications. High quality colonoscopy needs a good bowel preparation. 
The ideal bowel cleansing agent and regimen should completely empty the colonic contents without causing macroscopic or microscopic changes to the colonic mucosa. The prep agent and the diet restriction should be patient friendly ( easy to take and well tolerated), have minimal adverse effects and be cost‐effective. 
We recommend to follow the international guidelines to obtain the best quality result.