Symptomatic Hyponatremia following Bowel Preparation for Colonoscopy: A Case Report

Colonoscopy is considered a gold standard tool for the diagnostic evaluation of colorectal diseases. Bowel preparation, a pre-requisite for a colonoscopy, usually involves the ingestion of purgatives for the cleansing of the bowel so that visualization is not obscured during the procedure. Commonly used preparations are sodium phosphate-based solutions, sodium picosulphate, and polyethylene glycol. The use of such preparations is associated with electrolyte disturbances, commonly hyponatremia. Hyponatremia is usually seen with sodium phosphate-based solutions and is rare with polyethylene glycol. Symptomatic hyponatremia, however, is rare following bowel preparation and is attributable to other factors as well, such as the age of the patient, non-osmotic release of anti-diuretic hormone, and the procedure itself. In this report, we discuss a case of severe symptomatic hyponatremia observed in a 71-year-old gentleman who underwent polyethylene glycol-based bowel preparation for colonoscopy.