It is important to ensure that the bottle is kept upright at all times as some bottles contain corrosive additives.
Please ask for two bottles if you think that one will not be sufficient.
For example:
6.00am day 1
Empty bladder and discard the urine into the toilet. Pass all urine for the next 24 hours into the bottle.
6.00am day 2
Next morning, empty bladder into the bottle. This will complete the collection.