Survey of Polyethylene Glycol Effects on Serum Electrolytes

Colonoscopy and bowel preparation caused a number of serum electrolytes changes that may be dangerous in heart and kidney diseases and elderly patients. To determine the effect of serum electrolytes in patients who underwent colonoscopy and bowel preparation with PEG (Polyethylene Glycol) in Tehran Imam Khomeini hospital in 2008. Fifty nine patients who had been selected for elective colonoscopy after the detection of exclusion criteria were assessed prospectively. Serum level of sodium and potassium were analysed before bowel preparation with PEG (To), before colonoscopy (T1) and immediately after it (T2). Serum calcium and phosphorus levels were measured just before and after PEG. Four patients (6.8%) did not follow the research protocol and were excluded. Four patients (6.8%) developed hyponatremia in T1 that continued in T2. There were no significant differences in prevalence of Hyponatremia and means of sodium serum levels in To, T1 and T2. Although there was a significant trend to decreased means of potassium levels of T2 versus T1 (P