Given that we are all different and we eat differently, ileostomy frequency is usually dependent on when and how much you eat and drink. It also depends on whether or not you are missing any of your small bowel. Mine is intact, but my entire colon is MIA. I typically empty my bag 5-7 times during waking hours, which are usually 8 to 12 for me. During the night, I will typically get up around 3:00 AM. If I have behaved myself with the nighttime munchies, there is usually nothing but gas to get rid of. Sometimes, there is enough that I will bother with it. My next time up is sometimes around 5:00 and sometimes not until I get up between 7:30 and 8:00. If the former, there will be gas to get rid of and some output. At that time, I will decide if I can wait or not. Then I get up and it starts all over again.
I do not have a problem with a lot of nighttime output. I do stay away from significant quantities of food after 4 PM, or so. And I try to limit my nighttime snacking. Especially the night before bag change morning. I do take 2 mg of loperamide every night about an hour and a half before sleep. I also add a couple of teaspoons of Benefiber and a couple of tablespoons of pea protein to my morning fruit smoothie (peaches, blueberries, raspberries, strawberries, blackberries, and the occasional banana). But, I eat pretty much anything I want. Lately, it has been a curry I made the other day.
Warrior gave some good advice to bulk up your output. The idea is to let it thicken in your bowel so that it slows down and your intestine has more of a chance to absorb liquid. The idea is to find what works for you. A happy medium, so to speak. Too watery and you are constantly at the toilet. Too thick and you run the risk of pancaking. One thing you can expect at night, if you eat too much your bag will fill with shit. If you don't eat, your bag will fill with gas. It is the way of things. When you find the right path, you can get on your way.
Daniel