Is Patient Acceptability of Oral Sodium Phosphate as Preparation for Colonoscopy as Good as Is Claimed?

Abstract

Aim: Fleet phospho-soda as preparation for colonoscopy gives excellent cleansing but is often poorly tolerated. Company data claims that dividing and diluting the dose improves tolerance. However, in our experience patient acceptability figures with regards taste, side effects, and willingness to repeat are lower than those stated. This study compared two methods of ingestion of Fleet in terms of patient acceptability and efficacy. Methods: All patients attending out-patient colonoscopy from November 2002-November 2003 were randomised to one of two dosage schedules. Group 1; 2 × 45ml doses: Group 2; 6 × 15ml doses. Patients were allowed to dilute Fleet in water or a clear liquid of their choice. Patients completed a questionnaire detailing, compliance, taste, side effects, and their willingness to use Fleet again. Endoscopists, blinded to the dosage schedule used, completed questionnaires regarding procedure indication, preparation quality (excellent, good, fair, poor), completion, and findings. Power calculations were based on 85% of patients grading taste as good/OK. A 90% probability of detecting a 10% difference in the number of patients reporting acceptable taste required 115 patients per group. Results: 326 patients were randomised (Group 1 n=192; Group 2 n=134). There was no difference between the groups with regards age and gender. 34.7% of patients diluted Fleet in something other than water; 97.9% completed the preparation. Group 2 patients experienced significantly less nausea and vomiting compared with group 1 patients. There was no difference in any other patient acceptability parameter (table). There was no difference between the groups with regards excellent/good preparation (92.2% vs. 86.0%), completion rates (94.1% vs. 92.1%), or abnormalities noted. Diluting Fleet in anything other than water did not improve taste; 24.1% of those who diluted graded the taste as good/OK compared with 33.9% who used water (p=0.08). More patients who diluted Fleet in liquids other than water had nausea (68.1% vs. 50.9%: p<0.005) although there was no difference in any other parameter. Conclusion: Nausea and vomiting following Fleet is reduced by divided dosage schedules. Dilution does not improve taste or tolerance. Patient acceptability is much lower than suggested.