A case of Conn's syndrome revealed after oral sodium phosphate (Fleet) preparation for colonoscopy.

Oral sodium phosphate solutions (Fleet Mcneil Consumer Healthcare, Guelph, Ontario, Canada) are commonly used as bowel cleansing agents in preparation for colonoscopic exams; however, serious electrolyte disorders associated with oral sodium phosphate use have been described in case reports including hyperphosphatemia, hypocalcemia, hypomagnesemia, hypernatremia, and hypokalemia. We describe a 57-year-old patient with a past history of resistant hypertension who experienced severe symptomatic hypokalemia following colonic cleansing with an oral sodium phosphate solution. Further investigations revealed a serum aldosterone of 691 pmol/L and a serum renin level of 0.