How to prepare for a endoscopy?

I am joining the military and I ped my physical and asvab with great results but since I have a history of having eosinophilic esophagitis when I was obese in my teens, I was automatically disqualified and require a waiver. I have lost over 50 pounds in the span of 3 years and was told that I do not require any further treatment. I tried having a doctor give his opinion after reviewing my records but that wasn't enough. What my doctor suggested is that I get an endoscopy and give the military facts instead of opinions. The endoscopy should be fine, but I am worried about this because I do not know what to expect, given my history and all. I do sometimes have symptoms of indigestion and feeling bloated after eating but it rarely occurs and happens usually when I eat a lot of pizza and drink soda, or other acidic foods. Hopefully it all turns out well but is there anything I can do from now until the 25th of this month to "better my results"? I do not have any knowledge of this matter and if the truth is a week of preparation is not going to do anything, then so be it. But if there is anything I can take over the counter, or avoid certain foods, to better prepare my G.I., it would be great to know. For example, a probiotic dietary supplement. Thank you.