HIGH DOSE SENNA OR POLY ETHYLENE GLYCOL (PEG) FOR ELECTIVE COLONOSCOPY PREPARATION: A PROSPECTIVE RANDOMIZED INVESTIGATOR-BLINDED CLINICAL TRIAL

Nowadays colonoscopy has become an essential procedure for detection and treatment of colonic lesions and investigating the bowel. Preparing a clean colon before colonoscopy is essential to obtain an accurate diagnosis and meaningful visualization during colonoscopy.1 An ideal colon preparation should meet the following criteria: 1) easy on patients; 2) need little time; 3) have few adverse reactions; 4) clean colon mucosa adequately; and 5) have the best cost -effectiveness profile.2 In the past decades, several studies have been performed and various bowel preparation methods have been proposed including castor oil, anthraquinones, Diphenylmethanes, Phenolphthalein, Magnesium Citrate, Poly Ethylene Glycol (PEG), Sodium Phosphate (NaP).3–7 PEG and NaP preparations are the most popular regiments for colon cleansing worldwide.8 But despite their proven efficacy, they are still far from ideal. The unpleasant taste and large volume of PEG frequently lead to poor compliance with recommended dosing regimens, often causing patients significant dissatisfaction with the procedure.9–11 Most of studies that have been conducted to compare NaP and PEG solutions have suggested a superiority or equivalence of NaP in preparing mechanical bowel adequately and safely.12–15 In other hand, considering the financial as pects, NaP is more beneficial and increases the patient's compliance.13,14,16 However NaP has several limitations in the application such as fluid shifts and precipitating intravascular volume depletion and could not be used in patients with congestive heart failure, renal failure, and decompensate cirrhosis.17 Stimulant laxatives, such as Bisacodyl and Senna (an herb), and Anthraquinones, were widely used for colonoscopy preparation in past decades and now they are commonly used for treatment of constipation.4,17 However experiences are limited and results are conflicting on their use as single oral agents for colon cleansing.18–20 There are some studies that counteracted previous investigations and revealed that bowel preparation with Senna was more effective than PEG in achieving a successful preparation for elective colonoscopy and could be tolerated better.17,18,20 All of these show that the use of Senna in single for preparation is a controversial issue. In this study we aimed to compare the colon cleansing, difficulty of procedure and patient's compliance in patients who used Senna or PEG in preparation for colonoscopy.