There is a company called Nu-Hope Laboratories. They make ostomy belts that are wider than the usual thin, stringy 1 inch wide belts that cut into you, or ride up on your stomach. The Nu-Hope belt has a special ring that hugs and holds the flange / wafer in a 360 direction, not just on two tiny points on the side. The 360 hold allows you to feel your bag is on securely. You send them your waist measurements taken standing up, lying down, and they send you the belt.
There is also Stealthbelt.com. They make a neoprene waist band that has a special pouch to hold (and hide) your ostomy bag so it doesn't show under clothes and so the bag doesn't hang loosely. If you are bothered by heat and humidity, you can find cloth covers on Etsy. The cloth cover fits over the bag and keeps it away from your skin on hot, sticky days. You can empty your bag without removing the cover, that's the best part. Athletes use a stoma cap to protect their stoma. For people who want to cover their ostomy for intimacy, there is a site called wearclose.com that sells special covers. I did a lot of research when I still had my ostomy because I didn't know how long until I could have the reversal to my j pouch. I found all these interesting sites and helpful products, and I felt less vulnerable knowing there is so much out there to help ostomates. I'm managing with my j pouch, and I hope the above is helpful.