Two piece ostomy bags are ostomy systems where the skin barrier is not connected to the pouch. They are detached from one another when you purchase them. You buy the bag and flange separately and attach them yourself. These two supplies fit together via a plastic ring called a flange. It is important to purchase bags and wafers that are compatible with one another, as these supplies are not universal. Express Medical Supply offers flanges and wafers separately, or together in kits.

Two piece ostomy systems allow you to keep your wafer on for a longer period of time. Because the bag and wafer are separate, you can leave your wafer on your body and just empty or throw away the ostomy pouch when it becomes full. The ostomy wafer can be left on your body for up to four days. This makes a two piece ostomy system great for people with sensitive skin since you won't be changing your wafer as often. Another positive of two piece pouches is that they are convenient to change. You only have to remove your bag rather than remove your wafer and apply a new one. This is especially convenient in scenarios such as using public restroom or going to someone's house.

One thing to keep in mind with a two piece ostomy system is that it tends to be more bulky than a one piece bag and can be more visible under clothing. There is also a risk of the bag and wafer detaching from one another, which could cause leaks. Two piece ostomy bags are typically more expensive than a one piece bag. The choice between a two piece ostomy bag and a one piece bag comes down to personal preference and what makes you feel most comfortable. Once you heal from ostomy surgery, it may be beneficial to try both a one piece bag and a two piece bag to see which works better for your lifestyle.