Learn to get in and out of bed on your side. Get into bed by sitting far onto the bed and going down on your elbow while holding on to the mattress with the other hand and swing your legs up. To get up, roll over on your side and use your elbow to push up, while holding the mattress with your other hand and swinging your legs sideways off the bed.
Learn to use tools to help you with some of the chores requiring bending over. Don't, for instance, bend over to clean the bathtub. Use a broom and a cleaner. To pick something up, or to reach high shelves, get a clamp-type 'reacher'.
Learn to lift and carry on the side of your leg or hip, carry things high on your shoulders, or drag it or get some help. Not only do you prevent the pouch from loosening, your might also prevent a hernia. ( Ostomates get hernias easier than anyone else).