Colonoscopy is an important diagnostic and screening tool for colorectal cancer detection and prevention, and adequate bowel preparation is critical for successful colonoscopy. Complications related to colonoscopy, either directly or indirectly related to the procedure, are increased in elderly patients, and the risks and benefits of colonoscopy procedures need to be carefully considered in these patients. Recent studies have shown that 4 L polyethylene glycol with a split preparation is safe and effective for elderly patients, and is the preferred preparation for patients with medical comorbidities. Preparations containing sodium phosphate are generally not recommended for the elderly because of increased renal complications. In addition, a low-residue diet may aid in tolerance and willingness to undergo the procedure compared with a clear liquid diet, with comparable bowel preparation adequacy. Risk factors for inadequate bowel preparations include poor adherence to split preparation instructions or volume of solution ingested, and certain patient-related medications and comorbidities, such as diabetes, elevated body mass index, and antidepressant or narcotic use. Methods for achieving safe and adequate bowel preparations in the elderly include clear instructions, reminder calls, and case management for potential confounding patient-related factors.