Night studies for primary diurnal and nocturnal enuresis and preliminary results of the "clam" ileocystoplasty.
 Modified conventional urodynamic apparatus was used to provide overnight monitoring of bladder and rectal pressure.
 A group of 26 patients with primary diurnal and nocturnal enuresis underwent both daytime rapid fill cystometry and overnight natural fill cystometry.
 The overnight study was effective in detecting detrusor instability in 10 patients deemed normal on rapid fill cystometry; 6 of these have now undergone clam ileocystoplasty and 5 are dry; 3 are awaiting this procedure.
 The clam remains very effective in the management of patients with resistant nocturnal and diurnal enuresis if careful selection is adopted.
 Overnight cystometry has proved to be an invaluable adjunct to the investigation of patients with primary diurnal and nocturnal enuresis previously felt to be urodynamically normal.
