Discomfort In Stomach, No Pain. On Fluid Diet. Was On Junk Food. Could This Be The Reason?

I am a 21 year old male. About one week ago I began to feel discomfort just below my left rib cage and also near my left hip and lower back (left side). I went to the doctors a few days ago and he pushed around my stomach looking for pain but was no pain besides the basic tickle pain you get when someone pokes you. He told me to go on a clear fluid diet then move onto a full fluid one over the next few days. It is day 4 since seeing him and i have been eating nothing but home made soup (cabbage and beans) also having 1-2 fruit smoothies a day and have biked for 30+ min each day, Even today my stomach feels like its really busy. I used to be a big junk food eater so that is why he put me on this diet. He also says it may be a piece of poop trying to make its way through and so that is why he put me on fluids to help clean me out. The discomfort has subsided a lot since the first few days before going to the doctors and even since then but i still feel discomfort from time to time. I was just hoping on getting some feed back/ 2nd opinion on this. perhaps what I may be able to take for the discomfort and how long pains may last?