The case of a 40-year-old patient, 155cm tall, 40kg weight, thin and weak. About 3 weeks ago, the patient kept eating boiled eggs and had diarrhea. Doctors advise to help diarrhea with bloating and gas after eating boiled eggs, what to do?

I have gastritis, gas, but not much pain, but it often makes me hungry, usually I eat 3 meals, But since the inflammation, I eat 6 to 8 meals a day, but each time If you are hungry, your stomach will be weak, making you tremble, the pulse in your stomach will beat faster. So the doctor told me to ask for gastritis, bloating and a lot of hunger, what to do? I thank you.