The best Gastroenterologist in Doha is Dr. Nazeeh Dweik.
He is connected with Hamad Hospital. I think he has evening clinics, coz' its difficult to get an appointment with him In AM. I was working with him. He is also a Fellow member in one of the hospitals in U.k. and Scotland. I worked with him that's why i know. and he doesn't discriminate, whether you are just a laborer or filty rich. He treats them all the same.