Is it IBS or what else??

I'm 26yrs old and have had gastro issues since I was 10.. But nothing serious ever.. In past 8yrs my liver enzymes seem to get elevated often.. Never really been concerned til these past 2yrs which I've had daily pain in that liver area (many say it's actually more like large intestine area) I have had ultrasounds but always come back normal.  Last month I had very elevated liver enzymes so my dr sent me to gastro dr but he did not ask me any questions just said it was due to drinking but i told him i dont drink. Then he said well you need to go on a diet and exercise because its prob fatty liver and i told him that i do exercise and eat healthier than most people.  Then he said well then its prob IBS and asked to do a colonoscopy.  I was in shock and have no clue how he could give me so many possible things that could be wrong with me without asking for a single symptom that I may have he asked no questions.  I also dont know if I should go ahead and do the colonoscopy.  My symptoms are pain in the right side around and under the rib cage and towards the back, i have constant bloating, on and off acid reflux sharp pains a lot of gas im constantly tired and just not sure what to do anymore. My life has stopped I dont go out because of constant pain and discomfort and its affecting my career too. Im frustrated with all the issues can i get some advice please!

One last thing went to see i chiro for some neck pain which he believes its due to a fall i had when i was younger (hit back of head on a brick) Without me telling all my other symptoms he told me i might have those issues now or would develop later due to my head injury.  Is this possible?