1pc vs 2pc Ostomy Appliance – OSTOMY TIPS (w/ video)

Ostomates have a lot of options to choose from when it comes to pouching systems, but it’s not always clear what the advantages and disadvantages are between a one-piece or a two-piece system. I hope that you’ll be able to learn the differences in the following post.


One-Piece vs. Two-Piece Ostomy Systems: An In-Depth Look!

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One-Piece Ostomy Systems

one-piece ostomy pouches
One-piece ostomy pouches from Coloplast, Perfect Choice and Nu-Hope

This is probably the ostomy system you’ll leave the hospital with. A one-piece means that the wafer (the part that sticks to your skin) is fused to your pouch right of the box. You can’t separate the pouch from the wafer.

Advantages of a one-piece appliance

  • Lower profile vs most two-piece systems.
  • Usually costs less than two-piece systems.
  • Fewer supplies to manage.
  • Some people find them more comfortable, especially if they have a less-than-perfect tummy or a hernia.
  • Zero chance of your bag falling off (but the wafer still can!).
  • Takes up less storage space, especially in a travel bag.
  • Less time to make an appliance change.

With a one-piece, the goal is simplicity. Some people love the minimal aspect of a one-piece, but there are some disadvantages too, assuming they are things that you find lacking.

Disadvantages of a one-piece appliance

  • Higher chance of getting an imperfect fit.
  • No option to rotate your pouch at will (an advantage if you use a Stealth Belt).
  • Can be more difficult to apply.
  • If you have to change the wafer early, you end up having to throw away the pouch, too.
  • If you have a problem with the pouch portion, you have to change the wafer, too.
  • No option to change to a different size/style pouch to accommodate different activities.
  • Can’t use pouch liners.
  • Can’t easily “burp” your pouch to get rid of excess gas.
  • Changing closed, one-piece pouches often can lead to skin irritation.

So while you have simplicity, you also lack some flexibility in options. In my experience, one-piece appliances are comfortable, but I always feel that I’m not getting a perfect fit around my stoma in the same way that I can with a two-piece, especially with seeing and/or correcting a gap that might be between my stoma and the cut-out in the wafer.

Two-Piece Ostomy Systems

With a two-piece, you have a separate wafer and pouch. You have an option of sticking the wafer to your skin before applying a pouch, which means that you can have a better look at your stoma and that usually results in achieving a better fit. There are several types of two-piece systems, and each manufacturer has their own coupling method. Here are the most common types:

Adhesive coupling

two piece adhesive coupling ostomy pouches
Two-piece ostomy pouches with adhesive couplings from Salts and Cymed

Like a hybrid of the two different ostomy systems, an adhesive coupling offers you some advantages of having a two-piece, but with the low profile and the added comfort of a one piece. This is done by replacing a hard plastic coupling with an adhesive coupling, which you stick onto a designated spot on your wafer. While some manufacturers say that you can remove the pouch and reapply/adjust it, many ostomates find that doing that is just asking for a leak.

Leaks are a big disadvantage with adhesive coupling systems. If you don’t stick the pouch perfectly onto the wafer, you’ll get a leak between your pouch and wafer. For that reason, I don’t suggest this type of coupling system to anyone who has dexterity, mobility or vision problems.

Some ostomates will stick the pouch to the wafer before applying the wafer to their skin. This effectively means that you are using it as a one-piece.

Mechanical coupling (with lock)

two piece ostomy pouch with locking coupling coloplast
Two-piece ostomy system with locking mechanical coupling. Coloplast Sensura Mio 2pc

This is an option that Coloplast has perfected, and it’s a huge part of the Click line of products they offer.

This system allows you to mechanically snap your pouch to your wafer and then lock it in place.

The beauty of this coupling is that it allows you to lock and unlock your pouch whenever you like, which is handy for rotating your pouch at will (like when using a Stealth Belt).

I feel completely secure when using a locking coupling, and if you have a high-output stoma which has resulted in your pouch falling off in the past, then this is a system you might want to try.

If you have dexterity or mobility problems in your hands, especially joint pains, then you might find the locking mechanism to be difficult to use.

I’ve read stories on forums where this has been an issue.

Another advantage that I’ve noticed when using 2pc systems with mechanical couplings is that it offers some basic level of protection against impact since the coupling is raised a bit.

If your stoma is flush or slightly protruded, then this might be a good alternative to stoma guards (again, for very basic protection).

Mechanical coupling (snap-in)

two piece ostomy pouches mechanical coupling
Two-piece ostomy systems. Mechanical snap-in style from Hollister on left. Locking couplings from Coloplast on center and right

This type of two-piece has a simple system that allows your pouch to snap into place on the wafer. This is common on Hollister products and works well. There is a small chance of your pouch falling off or leaking if it’s full and you’re doing a lot of running or jumping, but using a support belt or ostomy wrap will add an additional level of security to help prevent those issues.

One thing that I’ve found with snap-in couplings is that you can’t easily rotate them. You have to take your pouch off, rotate, then snap it back into place. While that sounds easy enough, I find that it only creates an opportunity for leaks.

Tip: I’ve found an easy way to help rotate these stubborn 2pc systems. Check it out HERE.

As I mentioned in the section above, this style of mechanical coupling may also give a basic level of stoma protection.

Advantages of a two-piece appliance

  • Allows for rotation of the pouch (some two-pieces).
  • Some mechanical coupling 2pc systems are easy to “burp” when gas builds up.
  • Can make it easier to get a perfect fit around your stoma (allows visual confirmation that the wafer was cut properly).
  • Allows you to replace your pouch without having to change your wafer.
  • In the case of an ileoscopy (scoped through the stoma), you likely won’t need to remove your wafer and can simply remove your pouch.
  • Allows you to swap between different pouches (that are compatible with your wafer); great if you use a high-capacity pouch at night and a smaller one during the day.
  • Can be used with disposable pouch liners.
  • Two-piece systems with mechanical couplings may offer some level of protection against stoma impact.
  • If you’re a colostomate, and you irrigate your colon, using a two-piece system allows you to easily remove your primary bag and swap it with an irrigation sleeve, then replace it when you’re done – all without having to remove your wafer.

Disadvantages of a two-piece appliance

  • Mechanical couplings add stiffness and bulk to the pouch; locking couplings are even more obtrusive
  • more expensive to purchase a separate wafer and pouch vs. a one-piece
  • some bags can detach or leak from the coupling
  • mechanical couplings are not ideal for hernias

Closing Thoughts

So which option is better for you? That’s probably something you’ll need to investigate yourself by sampling products from various manufacturers.

You may even decide to switch between systems, depending on your plans for that week or month.

Question: Are you a fan of one-piece or two-piece ostomy systems? Why/why not?

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1 year ago

Can the Osto-EZ Vent be used with a one piece Coloplast bag/wafer?

2 years ago

And Nuffy,Welcome to the forum. Its great to have another  voice.  We all benefit from all suggestions. We are all dealing with similar but different things and its great to have new new person in the community.

2 years ago

I’ve used the Hollister lock and roll ( velcro like stuff) bags for over four years now. The only kind I have ever used.  I have NEVER ever had a leak from that end of the bag.  I feel very secure with this system. It doesn’t seem to matter what the consistency of the output is…from liquid to thick.I do make sure the area is ‘clean’ , meaning rinsed or well wiped out after I empty it. If I am not rinsing I just wipe off the end really well. Then I push any remaining stool UP back into the bag as best I can.  The whole area to be rolled up should be as free of stool as possible.  After that I wipe out all I can reach from the opening, before rolling the whole thing back up.This sounds involved, but I literally do it in my sleep.Note: If you crease the opening BEFORE use ( vertically across the opening) , it makes it much easier to open it wide enough to wipe out later. I think this technique is explained elsewhere on VO.

2 years ago

Hi Bill, I mean the waxy ring under the flange/plate (so I was meaning preventing links at the top, actually). . I think most people use them, but I have heard of some that don’t seem to need them. LL

Bill Bell
Bill Bell(@bago)
2 years ago

I too have never had a failure of the lock and roll fastener in over 3 years.  On occasion I have rolled up the end a couple of times and put a rubber band around it.  This is to keep the plastic parts from scratching my leg while exercising.LL what kind of ring are you talking about?  I use a Nu Hope support belt that has a ring.  Maybe that is what you are referring to.

2 years ago

Hi Brenda, I use the Hollister with the Velcro lock-and-roll, and the Velcro has never failed (my ostomy is 15 months old). Once in awhile, if I want a little more security I use one of those little metal clamp/clips (like the ones Nuffy mentioned) which I can get from Office Supply. I also use a ring under the flange – the ring is a wonderful invention; without the ring I think I would get a leak. Best to you LL

Kianda Davidson
Kianda Davidson
2 years ago

I use Hollister 2 piece system and I haven’t had any issues

3 years ago

Hi Brenda,I am late coming on to this, but I was wondering if you have checked with your stoma nurse as to what body type you are.  Your body type may be enabling the leaks and you may not be using the best system for you. I found out that I have imperfections in the area around my stoma and discovered that I needed a convex system. I use the Sensura Mio Convex, and so far, no leaks. I also use a paste in the areas around the stoma that are indented and that helps the skin to stick more to the barrier. I hope this gives you something more to consider. Good luck!Stella

3 years ago

Hey Brenda…welcome. I tried a few bags when I first had my stoma and just love the Hollister 8331 bag. It is also a velcro roll up. I tried one with the clip and took it off within hours of trying it. It has never come undone on its own and I do a fair bit of bending, leaks aside.  Make sure you measure your stoma frequently, the bag company. will send you extra of the guides if you need some. Just ask. Hollister sent me a lot of them a while back. Always save the ones you do not use, you just never know when you will be glad you had them. Check and see if you have healed up differently then it looks. Mine went fro a circle to a D shape.  Use a mirror to check all sides and a flashlight if you need to, so you can see in the small shadow. Also, one issue I had was in getting the bag on… my  stoma had leaked fluid and it would get on the plate (wrong term…I am working on it) and then on my skin and then the leak. Usually at night due to laying down, or to pancaking.  Are you bending the plate forward to place it onto your tummy for the lower part first?  I use a q-tip or tissue to dry the stoma then finish putting the bag over the stoma without getting tissue on it or the plate, to put the rest of it on. Fanning the area with the plastic piece you took off the plate. Then immediately apply slight pressure to the edge around the the bag around your stoma to make sure you have it stuck there. I also tried and succeeded in using a warm hot water bottle to the sight after applying the bag, with a facecloth over my stoma. Lay down for this if you can. Be sure it is not too hot, you do not want to damage your stoma or the skin. I did this to make sure that the extra bit of warmth  to attached the bag better. I would rest about 5 to 10 with the bottle on my tummy.  If you have trouble getting the bags off at all, this is where the Spray Adhesive Remover comes in nicely. As far as feeling house bound, believe me that is a normal thing at this point for many. It does take time to develop the confidence of going out with a  pouch. You may experience noise  at home from your stoma,  no one sent me home with a silencer for my Rose, so be prepared that it will happen when you are out also. Sometimes  I place my hand over Rose to help quiet her a bit. Try naming your stoma if you have not and it is okay to change her name as you go, mine has had three names altogether. Rose being the best to date.  Make sure you have what you need with you for a trip out of the house just in case of a leak…Eric has a video on this. But make a few little trips out first before a lengthy one, giving yourself more time out each time when you’re ready. I started with small walks, they told me a lot about how Rose would do in public…not to mention myself.  All the best to you. Continue to heal well.Linda

3 years ago

Hi Brenda,I am sorry that  you are  having a hard time finding the right appliance/ fit etc. Like everyone says, it will get better! Not much help in the day to day, but you will find the right solution to this problem.Sometimes it is because that after only three months, you are still healing. Your body is getting used to the stoma. The stoma can change in size as you heal. I also use the Hollister, with the lock and roll closure that Eric mentions. It works great.If you have access to a stoma nurse, please see them.It is so frustrating to go though all this , but these things do work, and it will get better.Keep asking questions.

3 years ago

Sorry to hear you’re having such a rough time.  It took me a few months to find what worked for me, so don’t get discouraged.  I found for me that using a ring under the appliance helped with leaks, also using a belt helped.  Keep asking for samples until you find the right combination.  Good luck

3 years ago

Hi Brenda, A leak can sure knock any ostomates confidence. The one peice is a little tricky to put on compared to a 2 peice. (Just my opinion) their is always a reason for a leak and could be a very simple cause. Have you discussed the problem with your stoma nurse 

Brenda Fergus
Brenda Fergus
3 years ago

I’m so confused by all of this, I had a total proctolectomy on oct 11 2018 & I still can’t get used to this, I’ve tried almost every kind of bag from the samples they have sent me, I like the one piece but I have no luck, after a couple hours I end up with a leak, the hollister ones have been the best so far but I really don’t like the clip, so because of not knowing when I will leak I find myself being more house bound afraid to go out anywhere

2 years ago
Reply to  Brenda Fergus

Hi Brenda…don’t hide away, and stop your outside activities.. Do what I do,I have a simple method which I came up with, and it works day and night!! My Nurses love it when they see it. Also this method keeps that area extra clean…

(My Velcro fold over Hollister often fell apart too, and it worried me so I had find a way to prevent this from happening again!!) After you close the pouch outlet continue on from here…

I use a Winc Foldback clip which come in coated colours. I like the pretty pink, or use whatever brand you can find, and 4 sheets of toilet paper torn off in to one piece, and then folded horizontally, this is a must to prevent accidents; just wish I could show you a photo!

Here’s the link which is safe to show you the clip the clip I am speaking of…

Fold the piece of Toilet paper horizontally, (in half) then proceed to make a pocket to cover the outlet at the base of the Hollister pouch into little pocket; see my little diagram >> |__| << You will notice the toilet paper hangs over each side horizontally, now that's what we want to happen, so those ends will then fold underneath to make a firm pocket at the base of pouch then place the clip onto your pouch making sure the ends of toilet paper are tucked in, and in place then place the onto your newly made pocket, and then clip the little wings upwards to lock clip in place, that way the paper pocket doesn't come apart…

As an alternative you can also buy some disposable chuck super wipes which come in blue, pink, yellow, or green packs of 20 or more, or you can buy a large roll which I did, and just cut to size. These can be washed in the washing machine daily, and last for yonks! To be honest I found using these was way more economical than using toilet paper…Entirely your choice…

Superwipes link!!

Good luck Brenda and I hope this works for you, and you can understand my instructions…

All the best,

3 years ago

I used to be a very happy user of Convatec 2 piece with snap fit. Unfortunately, the plastic ring began giving me skin irritation. Only fix was to shift to 1 piece, Hollister soft convex. Trade off is that while it isn’t as convenient to line up wafer hole, the more flexible one piece seems more resistant to pancaking.

3 years ago

Thank you for very clearly explaining the difference between a one and two piece system. I’ve been using a two piece Convatec system for several years, and they last an average of 5-7 days, depending on how often I shower. I would like to know if you have had any experience with a waterproof cover I would love to shower every day, but the wafer just doesn’t hold up for more than 2-3 days. That gets too expensive for my budget to handle. Thanks for listening

3 years ago

With the two piece system how many days can i use one pouch? And the wafer?

3 years ago

2 pc is the way to go now i just have to convince my insurance company. and put the case of one pc leak bags on ebay

4 years ago

I like the two piece as I use the disposable liners that are so great and easy.

Juraj Gašparík
Juraj Gašparík
4 years ago

Prosím vysvetliť načo je na ileostomickom jednodielne vrecku Sensura Mio 16415 maxi krúžok, ktorého vrch sa nedá odlepiť a preto sa neviem zbaviť tlaku v sáčku. Dočítal som sa , že ten krúžok vie znížiť tlak až o 61%. Len neviem kedy a či sa dá NATO spoľahnúť, keď sa mi po 1-2 hodinách nafúknuté sáčok s či mi nepraskne resp.nevytlačí obsah sáčku. Ďakujem. Gašparík.

5 years ago

I’m glad you found a system that works for you! I’d like to try some ConvaTec products this year, but I don’t have the type of stoma that would benefit from using a convex produt.

One-piece systems are great, and if they work for you, there’s no need to change to a two-piece!

Sue Hill
Sue Hill
6 years ago

I use a two piece that clips together, at first I found it a little bit bulky but then I accidentally found a great benefit. Because the bag is bulkier it gives my stoma that little bit more space (specifically height so it isn’t as squashed), and this has solved the majority of my pancaking problems :-)
I’ve never (touch wood) had a problem with the bag popping off the base, it’s very secure.
The bag has the loops so at night I can wear a tight belt to hold the bag into place which (touch wood again) has stopped leaks when the bag gets full

6 years ago

I like the one piece for the low profile but if I could only have one system it would be the two

6 years ago

I have used both methods and find the one piece is like going in blind!!!needless to say I use two piece system