Can the catheter bag be left on overnight?

No.

According to Baidu Health-related information: Catheter bags cannot be left on overnight. Catheter bags are often used for patients with urinary retention. It is usually recommended to open the urinary catheter every 2-3 hours during the day and to open the urinary catheter at night to drain urine from the bladder. Leaving the urinary catheter open for a long time can cause bladder atrophy, and can easily lead to bacterial growth and urinary tract infection.

The catheter bag is mainly composed of a plastic bag, a cross drainage valve, a pagoda connector, a drainage catheter, a urine sleeve, etc. It is a medical device for collecting urine.