Methods: There will be 400 patients included in the project with all indications for colonoscopy (age ≥ 18 years, no upper age limit) except the exclusion criteria. The patients will be offered to participate in the study at the Endoscopy unit when arranging the examination. In case of agreement they will sign informed consent and they will be educated about the correct process of bowel preparation. They also get all the instructions in printed version and questionnaire of preparation tolerability. The advantages for the patients in study will be earlier date of colonoscopy. On the day of colonoscopy, the patients will submit the questionnaire and undergo standard colonoscopy examination.