Is this really IBS?

I have had IBS for 14 years, but for the past 14 months I have been experiencing strange new symptoms including fatigue, arthritis, intermittent fevers, bloating, gas, migraines on one side, high blood pressure, numbness and tingling in my extremities, rapid pulse rate, and abdominal pain. I had many tests done to check for thyroid, rheumatoid arthritis, heart condition, infection, cholesterol, diabetes, etc., all the tests except my SED rate and strep titers came back normal. Six months ago I began chronic diarreha with blood and mucous. My GP sent me to a Gastroenterologist who wanted to to a colonoscopy,

So three weeks ago I had my colonoscopy and 11 biopsies, I also had a very large adenomatous polyp removed which was causing some blockage. I still continue to have the blood and mucous d, spasms, abdominal pain, arthritis, and gas, but even though there was visable swelling and inflammation, the biopsies came back normal, so no UC or Chron's. Very frustrating, that I didn't get a diagnosis, but because the polyp was precancerous, they want to do a scope on me every three years so at least if I continue with these problems, there is a chance of finding something eventually that could lead to a diagnosis.

The GI says it is just the IBS, but I have been diagnosed with this condition for 14 years and never had any of these symptoms before. Antispasmodics, and changes in diet do nothing to relieve my symptoms, the antispasmodic works for an hour or 2 and then I have to take another. I have been popping the immodium like candy.

I am so fatigued. I am going to go back to my PCP and have lab work for thyroid, it's been over 15 months since I had it done last and it showed low/normal and the Dr said not enough to warrant drugs, but it may have changed, so worth checking since the fatigue is unbearable lately.

Also decided to do pre and probiotics and the GI said that wouldn't hurt, and suggested a bulk fiber suppliment as well to see if that helped any. *sigh* I feel like the colonoscopy was not a waste since I had the polyp and it was precancerous, I am only 29 so if I had waited, it could have been cancer, I am thankful for that. I joined the wellness center as this polyp has me motivated to lose my extra 45 pounds and get as healthy as possible. It was scary seeing that huge thing in the pictures and know it could have turned into cancer. Now I just need to find the energy to exercise.

I am just worried it is more than IBS since these symptoms are new and I am suffering so much more than I ever had in 14 years of having IBS.

What am I doing wrong? What can I do to get this to end and feel better again? Is this really IBS?

I try to get my small bowel checked, just in case. Several of the symptoms you mentioned sounded like Crohn's. It is possible for it not to be detected if only your colon was checked and the disease is in your small bowel. I really hope it's not but if I were you this is where I would go next.