The preparation for a colorectal cancer screening will depend on the type of screening being performed. When undergoing a colonoscopy screening, specific instructions on how to prepare will be given to you by your gastroenterology team ahead of your scheduled exam to clean out your large intestine. There may also be detailed instructions to follow in the days leading up to your screening. It is imperative to comply with your gastroenterologist's instructions to help ensure they can observe any areas of concern when performing your screening for colorectal cancer.