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What causes stoma bags to leak?

There are a number of reasons why stoma bags can leak. Most issues around stoma leakages bag can be resolved relatively quickly by making slight adjustments, swapping to a new product or even altering your diet slightly.

We have put together a few suggestions on how you can reduce the chances of a leakage occurring.

Uneven Skin

Leakages can happen when the skin surrounding the stoma opening isn’t completely even. This is usually caused by scarring or skin folds and means that a baseplate can’t sit flush against the skin. Output can leak into these tiny gaps and cause skin soreness.


  • Skin pastes such as Orabase® Paste are available and can help to ‘even out’ the surface of the skin, allowing the appliance to fit smoothly.
  • Products such as Stomahesive® Seals offer a simple and effective way to protect the skin around the stoma site. They can be custom moulded or stacked to fit individual needs. They can also be broken and rejoined and also used in combination with paste. The seals are alcohol free.

Changes to your stoma shape and size

Your stoma naturally changes size and shape and this is something you must bear in mind if you use cut-to-size baseplates. Following surgery, your stoma will usually shrink as it begins to heal.


  • Regularly measure your stoma, even when you feel that you’ve fully healed from surgery. Weight loss or gain or pregnancy can cause the stoma to change the size, even years after surgery.
  • If you find that you still have leaks, despite regularly measuring your stoma, you could consider other products.
  • Mouldable products may be a good option as its unique technology moves with your stoma for a snug a and secure fit. Another advantage of mouldable products is that they don’t need to be cut, saving you time.


If the bag fills unexpectedly then it could be down to a change in diet, a stomach upset or even something like nerves and stress can affect your output.


  • Stay Hydrated! With a stoma it is important to stay hydrated and drink plenty of fluid- at least 6 cups a day (or at least 8-10 cups a day if you have an ileostomy)
  • Watch out for beers and fizzy drinks which may cause problems with diarrhoea and wind.
  • Try to include a range of foods from each of the following food groups to make sure you have a balanced diet:
    ○ Protein-rich foods such as meat, fish, eggs, nuts, lentils and beans.
    ○ Protein and calcium-rich dairy foods such as milk, cheese and yoghurt.
    ○ Starchy foods such as bread, rice, potatoes, pasta.
    ○ Fruit and vegetables.
    ○ Fat. Fat is an important source of energy. Include olive oil in cooking, butter in mashed potatoes and full cream milk in drinks and milk puddings. By including oily fish in your diet at least twice a week, you can also ensure you're getting an adequate intake of Omega-3 essential fatty acids.
    ○ For most people, limiting their intake of fizzy drinks and spicy foods is helpful, as they can cause gas which can cause ballooning.


Ballooning, is when the bag fills with air, can cause the pouch to detach itself. If you experience this without any spare supplies, it can be an embarrassing and stressful situation.


  • You could consider trying a bag with a filter, which allows the air to be released. Stoma bags such as the Esteem® + Convex Invisiclose Drainable Pouch with Lock-it Pocket is an all-in-one solution that combines the baseplate and pouch in a single unit. The Esteem® + pouching system offers the latest technologies including a state of the art filter with anti-clogging film layers – these prolong the life of the pouch, keep the pouch flat and virtually eliminate odour
  • If there are any creases, folds or gaps in your baseplate, these also need to be filled to avoid leaks.
  • A stoma paste can be used to fill in these gaps.
  • Products such as Diamonds™ Gelling and Odor Control Sachets help solidify liquid contents and reduce or eliminate excess gas, which enables you to achieve a flatter, more discreet pouch.


Some stoma bag wearers find that pancaking is a problem. This happens where there is an air vacuum in the pouch, so the pouch essentially seals itself as the sides stick together. The output can’t drop into the bottom of the bag and therefore collects near the stoma site. Pancaking can cause the bag to lift and output to come into contact with the skin, which can be become sore and irritated.


  • The most important thing to try over a period of time is to increase your fluid intake. If the stool is very sticky try altering your diet, particularly your fluid intake as this can often make a difference to the consistency of your stool.
  • Increase your fibre intake as this can also help alter the consistency of the stool.
  • Towards the top of the appliance, there is a filter, which allows the gas to escape. Sometimes the filter works too well and causes the bag to suck together it is worth placing a filter cover over this to allow the gas to create a bit more space for the stool to move down in the bag.
  • By covering the filter any gas is trapped inside the pouch and usually preceding every bowel motion is a little wind, which inflates the pouch slightly allowing the motion to pass freely into the pouch (especially if it is oiled inside).
  • You can also grease the inside of your bag with oil (olive oil or baby oil although this can sometimes lead to shorter wear time). This helps the stool to slide down inside the bag.
  • Always make sure you discuss this first with your stoma care nurse.


Occasionally you can experience an allergic reaction to the baseplate of the bag. This usually results in a rash under where the baseplate was attached, itching and weeping of the skin. Your stoma nurse should be able to offer help in reducing the rash and recommending other products for you to try. Any skin irritations can affect the adherence of your stoma bag and result in leaks.

Find the right product mix for you

There are many stoma products and accessories that are designed to ensure good skin health and help prevent leakage. Every stoma is unique, so you will need to determine what is best for you by working with your stoma care nurse, as well as trial and error.


  • If you have broken skin around your stoma, use a stoma powder (not talcum powder) such as Orahesive® Powder to absorb moisture and protect your peristomal skin.

Ill-fitting Skin Barriers

A well-fitting baseplate is your best defence against skin complications. Baseplates provide the necessary barrier between your skin and stoma output, allowing you to remain secure, comfortable and irritation-free. It is so important to ensure that your stoma and skin barrier fits properly and that any output flows into your pouch without leaking under the skin barrier.

Measuring your stoma is essential as your stoma can change both shape and size.

  • Watch our video on how to measure and size your stoma correctly Click here
  • When applying the base plate, make sure it fits where the skin and stoma meet.
  • Check that no skin is showing between the skin barrier and the stoma.
  • If you have recently had surgery, it is important to measure your stoma each time you apply your bag.

Not changing/emptying your bag enough

It is important to change your stoma bag on a regular basis before it is susceptible to leakage. An overfilled or overweight pouch causes undue strain on the base plate attached to the skin, which could lead to leakage.


  • Base your wear time on personal preference, your unique stoma, and your output.
  • Change your pouch on a regular basis before it gets too full and leaks.

Removing your base plate

Take special care when removing your stoma base plate. Improper or rapid removal of your skin barrier could cause skin stripping. The associated damage could lead to irritation, pain, and leaks.


  • Take your time – gentle and slow removal works best.
  • Gently peel the barrier away from the skin, starting at the top and working downwards, while pressing against the surrounding skin.

Products such as Niltac™ sting-free Adhesive Remover can help to easily and rapidly release appliances or dressings adhered with adhesive and helps minimise skin stripping that causes pain.

Exercising with a stoma

If you find that leaks tend to happen during exercise, or when you move in a certain way such as twisting or bending down, it could be that the bag isn’t secure enough.

Make sure your stoma bag is secure during exercise or physical activity. If you are participating in sporting activities or other forms of exercise, you can wear certain clothing or accessories that can help ease your concerns.


  • Use a support garment or an adjustable stoma appliance belt, to keep the bag securely in place.
  • Products such as the Natura™ Mouldable baseplate makes pouch application much easier and more comfortable - while delivering the proven skin protection of ConvaTec Mouldable Technology™ that provides a custom fit to a stoma.
  • Try different sports attire, such as running tights or Lycra® shorts, to see what works best.
  • It’s also a good idea to empty your pouch before exercise.


What to do if you have a leak

If you are experiencing any issues with your stoma, it is best to seek advice from your Stoma Nurse and investigate what is causing the issue. If you would like advice on your stoma please call our advisors on 0800 467 866 or visit

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