A Foley bag is the collection bag attached to a Foley catheter, a flexible tube inserted into the bladder to drain urine. The catheter itself has a small balloon at its tip that holds it in place inside the bladder, and the bag hangs below to collect urine as it flows out continuously. If you or someone you care for has been sent home with one, understanding how it works and how to maintain it makes a real difference in comfort and avoiding complications.
Why a Foley Bag Is Used
A Foley catheter and bag are placed when someone can’t empty their bladder on their own or when medical staff need precise control over urine output. The most common reasons include acute urinary retention or blockage, monitoring urine output in critically ill patients, and use during and after certain surgeries. They’re also used when a person needs to stay completely immobilized after trauma, when severe wounds in the pelvic area need to stay dry to heal, and in hospice or palliative care for comfort.
Some people use a Foley catheter temporarily after a procedure, while others need one for weeks or months due to chronic conditions affecting bladder function.
Types of Drainage Bags
There are two main types of bags, and most people with a long-term catheter switch between them throughout the day.
Leg bags are smaller bags that strap to your thigh or calf under clothing. Most people use a 500 mL bag, though 750 mL and even 1,300 mL options exist for wheelchair users or anyone who can’t empty as frequently. Because they’re discreet, leg bags are the go-to choice during the day when you’re up and moving.
Overnight (bedside) drainage bags are larger and designed to hang from the side of the bed. They hold significantly more urine so you can sleep through the night without needing to empty them. Many people connect the overnight bag to their leg bag tubing before bed, then disconnect it in the morning.
How Positioning Works
The single most important rule with a Foley bag is keeping it below the level of your bladder at all times, whether you’re lying down, sitting, or standing. Urine flows into the bag by gravity. If the bag sits higher than your bladder, or if the tubing loops upward, urine can flow backward toward the kidneys. This backflow (called reflux) can cause a serious kidney infection.
When using a leg bag, the straps should be snug enough to hold it in place without pinching the tubing. At night, hang the bedside bag from the bed frame or a hook, never on the floor, and position it low enough that you can move in bed without pulling on the catheter.
Emptying the Bag
You should empty the bag before it gets completely full. A full bag creates back-pressure that can push urine toward the kidneys, just like poor positioning. Most leg bags need emptying every few hours depending on your fluid intake. To drain it, open the valve at the bottom of the bag over a toilet or measuring container, let the urine flow out, then close the valve firmly. Wash your hands before and after, and avoid letting the drain spout touch the toilet rim or any surface.
Cleaning and Replacing Bags
Leg bags can be reused for a period if cleaned properly. A common recommended method is rinsing the bag with a 1:1 mixture of white vinegar and water (for example, one cup of vinegar to one cup of water), which helps control odor and reduce bacterial buildup. Rinse the bag with this solution, let it sit briefly, then drain and allow it to air dry. Overnight bags are typically replaced more frequently since they’re harder to clean thoroughly.
Even with good cleaning, bags don’t last forever. The tubing can discolor, develop a film, or start to smell despite cleaning. Your healthcare team will advise how often to replace bags based on your situation, but swapping them out regularly is a straightforward way to reduce infection risk.
What to Watch For in the Bag
The bag gives you a daily window into what’s happening with your urinary system, so it’s worth paying attention to what you see.
- No urine draining: First check for kinks in the tubing and make sure the bag is positioned below your bladder. Confirm the leg straps aren’t squeezing the tubing shut. If there’s no abdominal discomfort or urge to urinate, drink two glasses of water and wait 30 minutes. If urine still isn’t flowing after that, seek medical help.
- Cloudy or foul-smelling urine: This is one of the earliest signs of a urinary tract infection. A strong, offensive odor combined with cloudiness is worth reporting to your nurse or doctor promptly.
- Blood in the urine: Unless you’ve recently had surgery on the prostate or bladder, blood in the bag should be assessed immediately by a healthcare provider.
- Sediment or grit: Small particles can accumulate in the bag or tubing over time. Increasing your fluid intake helps keep urine diluted and flowing freely, which reduces buildup.
Reducing the Risk of Infection
Catheter-associated urinary tract infections are one of the most common complications of having a Foley catheter. Bacteria can travel up the tubing into the bladder, and the longer a catheter stays in, the higher the risk. A few habits make a meaningful difference.
Keep the drainage system closed. Disconnecting the catheter from the bag unnecessarily introduces bacteria. When you do need to switch between a leg bag and an overnight bag, clean the connection point and work quickly. Wash your hands thoroughly every time you handle the catheter or bag. Clean around the catheter entry site daily with soap and water. And keep the bag off the floor, where it can pick up bacteria from the surface.
The most effective way to prevent infection is removing the catheter as soon as it’s no longer needed. If you’re managing a catheter at home and aren’t sure whether you still need it, that’s a conversation worth having with your care team at your next visit.