We report our experience with severe complications of sodium phosphate enemas. Eleven elderly patients received Fleet enemas for constipation. Three patients received 500 to 798 mL, and 8 received a standard 250-mL dose. Most presented within 24 hours with hypotension and volume depletion, extreme hyperphosphatemia (phosphorus level, 5.3-45.0 mg/dL), and severe hypocalcemia (calcium level, 2.0-8.7 mg/dL). Hypernatremia and hypokalemia were seen in most patients. Acute renal failure was present in all patients. Two patients required urgent hemodialysis. Five patients died (45%). One patient was autopsied. Calcium-phosphate deposition within the renal tubular lumens was found. Following an educational campaign, the use of Fleet enemas was reduced in our hospital by 96%. Sodium phosphate enemas, even in standard doses, may lead to severe metabolic disorders associated with a high mortality and morbidity. Their use should be limited to low-risk patients only.