External female urine collection devices share an important characteristic: they collect urine outside the body rather than requiring a catheter to be inserted into the bladder. But that does not mean all external systems work in the same way.
One of the most important differences is how urine moves from the woman to the collection container.
Some external female catheters use suction. Others use gravity. That difference affects the equipment beside the bed, how the system is set up, what caregivers need to monitor, and what happens when the woman changes position.
For a caregiver choosing a system for home use, understanding that mechanism is more useful than simply asking whether a product is an “external female catheter.”
What does “external female catheter” mean?
An external female catheter or external female urine collection device collects urine without entering the bladder. External urinary catheters are available in different designs and materials, and appropriate use, skin care, hygiene and patient education remain important regardless of the particular device.
The term describes a category, however—not a single technology.
Two devices can both be described as external female urine collection systems while relying on quite different methods to move urine away from the body.
For a caregiver, the first practical question therefore becomes:
Does this system use suction, or does it drain by gravity?
How does a suction-based female urine collection system work?
A suction-based system places an external collection device against the female anatomy. Urine enters or is absorbed by the collection material and is then moved through tubing by negative pressure into a collection canister.
PureWick is one widely known example. BD describes its Female External Catheter as using low-pressure wall suction or the PureWick Urine Collection System to draw voided urine away from the body. The catheter connects through tubing to a collection system or canister.
For home use, this means the external catheter is one part of a larger system. The caregiver also needs the manufacturer’s collection unit, tubing and canister, and the powered unit has operating and maintenance requirements of its own. BD’s documentation, for example, includes instructions for tubing connections, canister management and troubleshooting suction.
Other suction-based systems may work differently. PrimaFit, for example, is another external urine management system that uses suction, but its placement and securement design are product-specific. Its instructions call for connection to suction tubing and a canister and specify continuous low-pressure suction.
The important point is not that every suction device is identical. It is that suction itself is part of the urine-transfer mechanism, so a suction source and compatible collection equipment are necessary parts of the system.
How does a gravity-based system work?
A gravity-based external collection system does not use a powered suction source to pull urine away from the body.
UriCap Female is an example. The device is positioned externally around the urethral opening and connects through tubing to a standard urine collection bag. TillaCare’s product information specifies that UriCap relies on gravity and does not require external suction or glue.
Gravity, however, has its own setup requirements.
For urine to drain properly, the collection bag needs to remain below the appropriate body level. UriCap’s user and training materials instruct users to keep the urine bag below the bladder or urethral level, provide enough slack in the tubing, and reposition the bag when the woman changes position.
So “no suction” does not mean “no setup.” It means that the movement of urine depends on gravity rather than a pump.
Suction versus gravity: what changes at the bedside?
For home caregivers, the distinction becomes easier to understand by looking at the actual equipment and routine.
| Suction-based system | Gravity-based UriCap Female | |
|---|---|---|
| How urine is moved | Suction draws or wicks urine into the collection system | Gravity drains urine through tubing |
| Suction source | Required | Not required |
| Collection equipment | Compatible canister/collection system | Standard urine collection bag |
| Power at bedside | Required for a home powered suction system | No powered pump required |
| Tubing | Connects device to suction/collection system | Connects UriCap to urine bag |
| Positioning consideration | Follow device-specific suction, placement and airflow instructions | Bag must remain below urethral level and tubing must allow drainage |
| Position changes | Follow the manufacturer’s placement/repositioning instructions | Check placement and manage bag/tubing when changing position |
This table should not be read as a scorecard.
A powered system is not automatically inappropriate because it requires more equipment, and a gravity system is not automatically appropriate because it does not require a pump. The woman’s anatomy, mobility, care plan, nighttime routine and ability to use the particular device all matter.
The practical question is which system’s requirements fit the care situation.
What does the difference mean for nighttime home care?
Imagine preparing the bedroom before the first night of use.
With a suction-based home system, the caregiver needs to understand how the collection unit is assembled, where the unit and canister will sit, how the tubing connects, how the device is positioned, and what to check if suction is not working as expected.
With a gravity-based system such as UriCap Female, the caregiver instead needs to plan where the urine bag will hang, make sure it stays below the required level, provide enough tubing slack for movement, and check device placement after transfers or position changes. UriCap’s user guide specifically addresses bag positioning and reinforcement of the device after movement.
Neither routine should be improvised for the first time in the middle of the night.
Training matters because the collection mechanism is only one part of successful use. Placement, tubing, hygiene, position changes, emptying the collection container and knowing when to stop using the device all need to be understood in advance.
What about movement during the night?
Movement deserves particular attention because external collection devices depend on maintaining appropriate contact and positioning.
Manufacturer instructions differ.
For example, PureWick instructions describe specific placement positions and require the catheter to remain connected to the suction system. Current PureWick Flex instructions also specify replacement intervals and precautions involving airflow and skin condition.
UriCap instructions tell caregivers to check the device after the woman turns or changes position and to manage the urine bag before position changes. The bag remains below urethral level so gravity drainage can continue.
A caregiver should therefore ask more than “Can this be used at night?”
Ask instead:
What exactly must I do when she turns, sits up, transfers, or gets out of bed?
The answer should come from the instructions for the specific device being considered.
Does suction versus gravity determine which system is better?
Not by itself.
It is tempting to turn the distinction into a simple comparison: pump versus no pump, complicated versus simple, or one technology versus another.
That would go beyond what the evidence supports.
External female urine collection devices differ in their design, indications, contraindications, placement requirements and care routines. Published research on female external urine collection has largely examined external wicking devices, often in institutional settings, rather than directly comparing suction-based and gravity-based devices head-to-head.
A 2024 systematic review found that implementation of female external urine wicking devices was associated with reduced use of indwelling urinary catheters. The overall reduction in indwelling-catheter-associated UTI rates was not statistically significant across all studies, although studies that described implementation protocols showed stronger results. The authors also noted that outcomes such as skin injury and device-associated complications were inconsistently reported.
That evidence is useful, but it does not establish that suction or gravity is inherently superior.
For home use, caregivers should instead compare the requirements of the actual products.
Questions to ask when comparing external female urine collection systems
Before choosing a device, work through the practical differences.
How is urine moved from the body? What equipment is required? Does the system need electricity or suction? Where does the urine collect? What must remain above or below the woman’s body? What happens when she changes position? How frequently are disposable components replaced? Who will apply the device? What training is available? What contraindications or exclusions apply?
Those questions often reveal more than a broad label such as “external catheter.”
They also help distinguish the initial purchase from the ongoing routine. Collection devices, bags or canisters, disposable components and replacement schedules can differ, so caregivers should understand both setup and recurring supply requirements before deciding.
Where does UriCap Female fit?
UriCap Female offers one approach to external female urine collection.
It is a non-invasive external female catheter that connects through tubing to a standard urine collection bag. Rather than using suction to pull urine into a canister, it relies on gravity drainage and does not require a powered pump or adhesive.
That mechanism may be particularly relevant to caregivers who are comparing what equipment and routine they want to manage at home.
It does not eliminate the need for proper placement or caregiver training. The urine bag must be positioned correctly, tubing needs to be managed, and placement should be checked after movement. Caregivers should also review the product’s indications, contraindications and instructions before use.
The question is therefore not simply whether gravity sounds preferable to suction.
It is whether the complete UriCap system and its care routine fit the woman’s needs and home-care situation.
Before choosing, compare the whole system
When comparing external female urine collection devices, look beyond the catheter itself.
Understand how urine moves, what equipment needs to sit beside the bed, what has to happen when the woman changes position, how often supplies need to be changed, and who will be responsible for the routine.
Suction and gravity are two different ways of solving the same basic collection problem. Understanding that difference gives caregivers a much better starting point for asking the right questions.
For caregivers considering UriCap Female, TillaCare’s home-use resources provide application guidance, user instructions and training materials explaining how the gravity-based system works. Product questions can be directed to TillaCare, while questions about whether external urine collection is medically appropriate should be discussed with the woman’s healthcare provider.
PureWick is a trademark of its respective owner. TillaCare is not affiliated with or endorsed by the owner of the PureWick trademark.