Howdy Gingerlee,
Like others have mentioned, it's important to keep hydrated. Drink lots of plain water and electrolyte beverages. I like Gatorade Fit (available from Amazon). Don't chug... only sip. Otherwise, you will pee most of it out and not absorb it.
4 months post-op, I passed out at work. Smacked my head on a machine. Luckily didn't break anything. Paramedics called. Spent nearly 2 days in the hospital. All because I was dehydrated. So drink... drink... drink.
I lost 64 pounds during my medical adventure. Didn't eat much for 2 months. Fortunately, I was about 45 pounds overweight before I got sick. If I didn't have that extra weight to lose... I would have perished. After surgery, I regained my appetite and started eating all the time like you. I'm now 8 months post-op and am forcing myself to eat less. I gained back 30 pounds and that's where I want to stay. I resist the urge to eat at night and have very little junk food or "fun stuff." My wife & I go out to dinner nearly every day. As soon as it's served, I cut it in half. Eat only half, get the rest to go. I have that for lunch the next day.
I've gotten to the point where I don't care when emptying my bag. If someone is in an adjacent bathroom stall.... Oh well... I just let 'er rip. The bag makes lots of noise, I use quite a bit of tissue. Other folks in there probably wonder what the hell is going on. I've learned, got an ostomy, check your modesty at the door.
Hope some of this helps