Inclusion Criteria:  Has given written consent to participate by signing the Informed Consent Signature Form Is at least 18 years of age and have full legal capacity Has an ileostomy or colostomy with consistent liquid fecal output (6-7 Bristol scale. Is currently using a SenSura® Mio flat product with open bag. Has had the ostomy for at least 90 days. Can use an ostomy product with a max cut size of 45 mm (1-piece) or 38 mm (2-piece).  Has experienced leakage** under the baseplate at least three times within the last fourteen days.  **Leakage defined as output/seeping under the baseplate (see appendix 7)  Has experienced symptoms of peristomal skin complications such as itching, burning, or pain in the peristomal area within the last fourteen days. **  ** Proper training of the PI and nurses in how to ask the subject about these symptoms is essential.  Is able to handle the electronic diary (questionnaire/photo) themselves. If needed, a trained spouse or caretaker is allowed to assist. Is able to handle (apply, remove, cut, etc.) the product themselves. Understands that any barrier products (film, cream, spray, wipes etc.) are not permissible during the investigation, and is willing to not use these accessories during the investigation. Is willing and suitable (determined by the Principal Investigator or designee) to use a flat custom cut one-piece open or two-piece open product during the investigation. Is willing to change the product (1-piece) or baseplate (2-piece) at least every fourth days.  Exclusion Criteria:  Is currently receiving or have within the past 60 days received radio-and/or chemotherapy.  - low doses radio- and/or chemotherapy (assessed by Principal Investigator) is allowed for other indications than cancer.  Is currently receiving or have within the past 30 days received topical steroid treatment in the peristomal skin area, e.g., lotion or spray.  Low dose systemic steroid treatment (e.g., inhalation) assessed by the investigator are allowed. Other systemic steroid treatment (e.g., injection or tablet) are not allowed. Is breastfeeding. Is pregnant based on urine pregnancy test. Has known hypersensitivity towards any of the products used in the investigation.