Endocrine Abstracts

Introduction: Bowel preparation is known to cause minor electrolyte disturbances. There are only five reported cases of severe electrolyte disturbances following bowel preparation that have caused seizures. We report the case of a patient with severe hyponatraemia and hypokalaemia, resulting in a seizure, following the administration of picolax.

Case report: A 60-year-old female patient with no significant past medical history and taking no regular medications presented with confusion following administration of picolax for an elective colonoscopy. On arrival her GCS was 14/15 (E4, V4, and M6) but minutes later she had a tonic–clonic seizure, with no urinary incontinence or tongue biting lasting 2 min. Following this, her GCS was 9/15 (E2, V1, and M6). Laboratory tests revealed a sodium level of 119 (135–145) and a potassium level of 3.1 (3.5–5.5). A CT head did not identify any cause for the seizure. Lumbar puncture was normal. Following i.v. replacement of electrolytes, sodium was measured at 137 and potassium at 3.4. Further investigations revealed a serum osmolality of 244 (282–295), urine osmolality 508 (300–900), and a random cortisol level of 1000 (raised – time dependent). Forty-eight hours later, GCS returned to 15/15. The patient had no recollection of events from after she took the bowel preparation. There were no neurological deficits noted.

Discussion: Severe hyponatraemia, hypokalaemia and associated seizures following bowel preparation are rarely described in the literature. Four of the five cases in the literature describe patients who have pre-existing medical conditions and are taking regular medication which could have contributed to hyponatraemia. We urge care to be taken when prescribing bowel preparation; particularly in those with pre-existing medical conditions and taking medications which can cause hyponatreamia, and to council patients when prescribing bowel preparation on the side effects.