[header] How to change a colostomy bag [title] Start by emptying your colostomy bag. [step] If there is urine or feces in your colostomy bag, it is important to empty these prior to changing the bag. The best place to do this is in the bathroom. 
Open the bottom of the bag over the toilet. For feces, you can gently squeeze it out of the bag; urine will automatically flow from the bag when it is opened.