Ostomy bags and pouches

An ostomy bag, more properly called a pouch, is the part of a pouching system that collects output from the stoma. It is the single piece of equipment an ostomate depends on most, and the one where a poor choice shows up fastest as leaks, sore skin and lost confidence.

This guide explains how pouching systems differ, what actually causes leakage, when convexity helps, and how the main manufacturers compare, so that samples can be requested with some idea of what to ask for.

Freshness check, September 2026 — we re-confirmed every product detail and link in this guide.

The honest starting point

The three global manufacturers — Coloplast, Hollister and ConvaTec — all make genuinely good pouches, and none of them is universally best. Independent stoma care nurses will say the same thing: the brand matters far less than the fit.

That is not a fence-sitting answer, it is the most useful thing anyone can tell a new ostomate. A perfectly engineered barrier applied to a stoma sitting in a skin crease will leak, and a mid-range barrier cut accurately to a well-sited stoma will not. Almost every “this brand is terrible” story turns out on inspection to be a fit story.

So the practical order is: get the fit assessed, then request samples from all three manufacturers, then choose on how your own skin responds.

What actually makes a pouch work

The barrier, not the bag

The pouch holds the output; the barrier (also called the wafer, flange or baseplate) is what keeps it in. Nearly every meaningful difference between products lives in the barrier: what it is made of, how it handles moisture, whether it is flat or convex, and whether it is cut to fit, pre-cut, or moldable.

Cut-to-fit, pre-cut or moldable

• Cut-to-fit — you cut the opening with scissors to match your stoma. The most flexible option, and necessary while a stoma is still shrinking in the first months after surgery.
• Pre-cut — the opening is already made to a fixed size. Convenient once the stoma has settled at a stable size and shape.
• Moldable — the barrier is shaped with warm fingers instead of scissors, so it hugs the stoma without a cut edge. Particularly useful for oval or irregular stomas, for people who find cutting difficult or intimidating, and for anyone whose stoma size is still changing.

Flat or convex

A flat barrier lies against the abdomen. A convex barrier curves outwards towards the skin, pressing the surrounding area down so the stoma protrudes into the pouch. Convexity is the standard answer to a flush or retracted stoma, or a stoma sitting in a dip or crease.

Convexity is a clinical decision, not a shopping preference. It comes in shallow, medium and deep, and applied to the wrong stoma it can cause pressure damage. It should be started on a stoma care nurse’s advice.

Drainable, closed or urostomy

• Drainable pouches empty from the bottom and are reused for one to three days. Standard for ileostomy and for liquid output.
• Closed pouches are removed and replaced when full, typically one to three times a day. Standard for a formed-output colostomy.
• Urostomy pouches have a tap or spout and connect to a night drainage bag.

Why ostomy bags leak, in the order worth checking

1. The opening is the wrong size. It should clear the stoma by roughly 2 mm, no more. Too large exposes skin to output; too small presses on the stoma.
2. The stoma is flush or retracted and a flat barrier cannot seal against it. This is what convexity exists for.
3. There is a dip, crease, scar or hernia near the stoma that the barrier bridges rather than fills. A barrier ring or paste fills it.
4. Wear time is too long. Changing after a leak trains a routine around failure; changing before it prevents one.
5. Skin was not fully dry, or has residue from adhesive remover or a moisturising soap.

Notice that only the second point is about the product. This is why switching brands so often fails to fix a leak.

How the main ostomy bag brands compare

Manufacturer	Signature technology	Stands out for
Coloplast (SenSura Mio)	Elastic adhesive that flexes with body shape	Body-shape fit and a discreet, skin-friendly profile; strong for active wear
Hollister (New Image, CeraPlus)	Ceramide-infused barrier	Protecting the skin barrier between changes; a strong first choice for sensitive or already-damaged skin
ConvaTec (Esteem, Natura, Moldable)	Moldable barrier technology shaped by hand	Oval, irregular or still-changing stomas, and anyone who would rather not cut

Top ostomy bags by category

These are the category picks. In every case, request samples before committing a whole month’s order.

Best ostomy bag for sensitive skin: Hollister CeraPlus

A ceramide-infused barrier designed to help maintain the skin’s own moisture balance between changes, rather than simply sticking to it. Where peristomal skin is already sore, itchy or stripped, this is the usual first thing a stoma care nurse suggests trying.

Best ostomy bag to prevent leakage: a correctly sized convex barrier

There is no single product answer here, and this is the honest one. If leaks persist with a flat barrier and the stoma is flush or retracted, a convex barrier in the appropriate depth, combined with a barrier ring to fill any crease, resolves the large majority of cases. All three manufacturers make good convex ranges; the depth and fit matter far more than the badge.

Best ostomy bag for an irregular stoma: ConvaTec moldable

The barrier is shaped with warm fingers to the exact outline of the stoma, with no cut edge, which suits oval or irregular shapes and stomas that are still changing size after surgery.

Best ostomy bag for active wear and swimming: Coloplast SenSura Mio

An elastic adhesive built to follow body movement rather than resist it, with a flexible, low-profile pouch. The usual recommendation for people whose main complaint is the appliance tugging or lifting during exercise.

Best ostomy bag for discretion under clothing: Coloplast SenSura Mio

A thin profile and quiet fabric backing that stays flat under fitted clothes. A pouch cover or wrap does more for discretion than any pouch alone, but among the pouches this is the flattest.

Best ostomy bag for beginners: a cut-to-fit or moldable one-piece

In the first three months the stoma shrinks, sometimes considerably. A fixed pre-cut size bought in bulk during that period usually ends up wasted. Cut-to-fit or moldable, in a one-piece for simplicity, is the safer starting point.

Best budget approach to ostomy bags

Where supplies are covered by Medicare, the NHS or private insurance, the cost question is largely settled and the choice should be made purely on fit. Where they are not, buying direct from a discount distributor is materially cheaper than retail, and manufacturer sample programmes let you test before spending.

Ostomy bags by stoma type

• Colostomy — output is usually formed and less frequent, so a closed pouch changed one to three times daily is common.
• Ileostomy — output is liquid to porridge-like, constant and enzyme-rich, so a drainable pouch and careful skin protection matter more. Barrier erosion is faster.
• Urostomy — a pouch with a tap, connected overnight to a night drainage bag to avoid the pouch overfilling during sleep.

What ostomy bags do not solve

A pouch holds output securely. It does not hold itself flat under clothing, take its own weight off the adhesive during exercise, or stop the outline showing through a shirt. That is what the support layer is for, and it is bought separately from the pouching system:

• Ostomy belts compared — take the weight off the adhesive and add security
• Ostomy bag covers compared — odour, comfort against the skin and concealment
• Ostomy wraps compared — hold the pouch flat for everyday wear and intimacy
• Ostomy underwear compared — high-waist briefs and boxers with a pouch pocket
• Where to buy ostomy supplies — suppliers, Medicare and insurance

The bottom line

Choose a manufacturer on how your skin responds, not on reputation. Get the barrier opening right to within about 2 mm, add convexity only on clinical advice, fill creases with a ring or paste rather than hoping the barrier bridges them, and change on a schedule instead of after a leak.

Do those five things and most pouching problems disappear without changing brand at all. If they do not, the answer is a stoma care nurse looking at the abdomen, not another order of samples.