I found not eating after 6pm helpful regarding sleep. For a while in the early days if I stuck to the above meant I only got up once in the night about 2am to empty the bag.
For some unknown reason it helped if I didn't look at the clock to see the time.
As you mentioned getting five or six hours of unbroken sleep is bliss. I often suffered with pain in my stomach which usually meant an adhesions flareup. I was advised by stoma nursing staff to take co-codamol. This worked threefold; It offered pain relief, slowed down my output and helped me sleep. I'm not advising anyone to take this medication. Professional medical advice is vital. This medication is codeine and paracetamol combined so needs careful monitoring.
