As much as I love my band, I have to say that it's a fickle mistress. It can take several fills to achieve optimal restriction, and then as you lose weight and the fat surrounding your inner organs (including your stomach) shrinks, your band will feel looser so you'll need more fill. Also, restriction can be affected by the time of day, the climate, medications, allergies, hormones, and the position of Mars in the sky. You'll feel more restriction when you're making healthy food choices of SOLID foods, less restriction when you're choosing to eat soft and slider foods (some of which are healthy, like yogurt, but a lot of them are high-calorie and nutrient-poor, like ice cream and potato chips).
We're all sick of dieting by the time we have WLS, but in a sense success with the band does involve dieting. Your band can't make good food choices for you, it can't make you exercise, it can't make you say no to trigger foods. That's all up to you. I'm over 4 years post op, 2 lbs. below my goal weight, with excellent restriction, and I still have to work on all of that in order to maintain my weight loss. It's a lifetime project.
Finally I have to say: just because you can eat anything or overeat doesn't mean you should. Overeating can indeed stretch your pouch and/or esophagus and it can indeed cause your band to slip. Nowadays self-control seems to be a no-no word, but portion control is up to you, at least until you learn your soft stops. Your band won't ring a bell or flash some lights when it's time for you to stop eating. You have to eat slowly and pay close attention to how you feel as you eat. Soft stops are usually subtle - a hiccup, a sneeze, a sigh, a burp, an urge to clear your throat. If you eat through that kind of signal, looking for your pre-op sense of satiety (what I call "Thanksgiving dinner Full"), you'll go on struggling indefinitely. Success with the band is a lot of work.
Although it's possible that you've stretched your pouch, only an upper GI study can prove that. If you go on overeating, it'll just make the situation worse. So I suggest that you make yourself do the evil D word (diet) for a week, pay very close attention to your satiety signals, keep a food log including the times of your meals or Snacks so you can get a handle on how long your satiety lasts, and only then go back to your bariatric surgeon to discuss another fill.
Jean