I just did a Google search on Bariatric surgery and coffee because I had the same question. Initially, while your stomach is healing it is to be avoided. The temperature and acidic content of the coffee are hard on the stomach. Later, diet-wise, coffee is thought to be an appetite stimulant and diuretic. Some people say this is a myth. Some doctors hold by it. Like you I have to have coffee. My doctor said if I HAD to, to limit it to one a day after 3 weeks post-op.