I just recently got over a diagnosis of colitis. I'm 24 years old 6"1 215lbs. I run 5-6 times per week and very healthy. Last wednesday I went to the doctor because i was having bloating, cramping and pain in my lower left abdomen. They diagnosed it with colitis and gave me meds to take for several days and then to come back for a follow up a week later. Yesterday i went for my follow up and things have gotten 99 percent better. The meds have worked and most of cramping bloating is gone. The doctor believed it was just an infection of the colon etc. Well yesterday after my visit I started having diaherrea. I did have blood work, urine tests and my stool all tested and examined and everything was completely fine. The doctor did not want to do a CT scan because my condition has improved almost completely and did not want to expose me to the radiation. The diaherrea is now gone, but there is a full feeling/discomfort now under my right rib cage. It does not hurt it just feels weird like there is extra air in there and sometimes I feel it a little bit in my upper right side of my back. Not painful just discomfort. I'm starting to wonder...I talked to the doctor about the poss of it being cancer or a tumor or liver cancer and he said highly unlikely. Could this be happening because the infection may not totally be out of my body or do you think this is cancer etc/something serious? These symptoms just started happening yesterday after my follow up and I have felt 99 percent better since taking the medicine etc. Is this something I should be worried about and should I go back to the doctor for this??? Please help...if additional info is needed let me know.