Can domperidone before every meal make the stomach "lazy", then when the treatment stop, the stomach stop working properly?

Med side effects: That is quite possible. It's not that the stomach muscles are "lazy". It just takes time--and each person is different as too how long it will take to restore normal gut movement and function. It's also possible that the condition you were being treated for still exists, or is perhaps only minimally better. I strongly recommend consulting with a gastroenterology specialist.