This is not a secret diet or something you may hear all talk about. It is just an idea of something that could help a lot of people to weight loss without stomach pain.
A big problem for diets is that you have to eat less. Eating less wil hurt your stomach, at least for first days. It is not a medical problem, it is a psychological one.
You already know that when you are hurt, the sensors tells your head that it something is not well, and the pain is at the brain level.
The same is when you eat less and your stomach is craving for food. Well, you can't administrate yourself a painkiller for stomach, but you have to know that it is only at your brain level. After few days you will find that the pain will gone a bit every day. That happens because the brain knows that it is something constant and will tend to get used with it.
If you were used to eat a lot, your stomach is big, and if you don't fill it your brain will not be happy about it and will force you to do so next time. If you can keep a low amount of food for let's say on week, it will start to get smaller so next week you won't need so much food to fill it up.
To cheat the relation between stomach and brain i come with an idea. Eat less but constantly. Eat something every hour, a banana, a half protein bar, an apple, some cereals, whatever you like. Keep it a low calorie amount and you will accomplish two things: your stomach gets smaller while it have no pain and you will lose weight because you eat less.
Would you give it a try ?