Table 1 Patient details.

Patient	1	2	3	4
Age/sex	13, female	7, male	14, male	13, male
Underlying pathology	Relapse of Crohn's disease	JIA, fasted for surgery	JIA with vomiting	Craniopharyngioma
		Post‐operative vomiting		Diabetes insipidus
NSAID	Diclofenac sodium	Ibuprofen, indomethacin, diclofenac sodium	Diclofenac sodium	Diclofenac sodium
Highest urea (mmol/l)	22	12.9	10.7	10.7
Highest creatinine (μmol/l)	629	146	376	226
Normalisation (days)	Permanent impairment	3	4	5

JIA, juvenile idiopathic arthritis.