I am an 18 year old male that enjoys an active lifestyle and takes time in ensuring proper nutrition intake. No diseases run in my family other than indegestion, burping, and acid reflex, sometimes constipation. I had mono about 5 months ago, underwent a cbc test and ultrasound of the belly. Blood was normal for mono, and spleen and organs were fine except I found out I have a second spleen. During mono I had bad pain in my left quadrant upper abdomen, which was the reason for the ultrasound. After I felt all better so did the pain in my side. I continued working out, getting stronger and bigger. For the past two weeks I have been experiencing somewhat the same pain, except no other symptoms. Except now the pain in a very dull ache, comes and goes, and slightly radiates to the thoracic back (left side). Doesn't hurt when I deep breathe, or when I dp certain movement or eat anything. Gas and belching has increased throughout the day, and stools have changed slightly (no more banana shape, just small pickle shapes lol). No discoloration. Experiencing no other symptoms. But, because of this pain I am having terrible long lasting anxiety (specifically health anxiety), and constantly worry the worst possible scenario. Question is: what could be causing the dull ache? The anxiety? Or is something wrong with me? I did take creatine for a month then stopped because of the pain. Maybe a buildup of it in my colon or something? Anyways, all opinions and advice is greatly appreciated!