What is wrong with me?

Okay, so I have been having very sore pains in my lower abdomen on the left and across the bottom of my waist for months. I have been told by my doctor that I have IBS and I have been suffering with nausea, vomiting, and frequent constipation despite taking Ducolax and Prilosec. I have had a EGD done (doctor found small reds spots on stomach lining), then I had a HIDA Scan done (everything is fine there). I had blood work and tests done on my liver, kidneys, gallbladder, and they are all fine. On Tuesday I had a colonoscopy done and one polyp was found and removed and it wasn't cancerous. I also have several hemorrhoids in my colon as well. It is now Sunday, and since Tuesday I still have a very constant sore pain in my lower abdomen and sometimes on my lower left abdomen. My doctor and many friends who have had a colonoscopy done said that I shouldn't feel pain but I do and it is very painful. I am at my wits end! What is wrong with me and what should I do?