ACE and diabetes mellitus: Adequate colon cleansing was negatively influenced by gender (female patients were associated with higher colon cleansing rate, p = 0.013), diabetes (p < 0.0001), previous pelvic surgery (p = 0.001), use of Beta-Blocker (p = 0.001), anti-platelet (p = 0.017), ACE-inhibitors (p = 0.001), the adoption of 4L PEG solution (p = 0.009), single-dose regimen (p < 0.0001) and low patients’ compliance (p < 0.0001).