What Could Ongoing Symptoms Of Nausea, Back Pain, Itching, Blood In Bowel Movements, And Stomach Pain Be Indicative Of?

Last week I awoke with extreme.nausea.amd lower back pain. That night I had such crippling upper wind pain what it felt like I had to.go to the hospital. They did bloods and urine amd was sent home. Pain continued and took mylanta and started to ease. I have had an itchy rectum for 6 yrs and countless drs visits told I have to live with it. I scratched and them went to the toilet and blood in bowel movement. Pain continues and I had diarhea that I couldn t hold. I took myanta amd it helped but felt the pain had to pass overtime. 4 days later I went no pain but blood in bowel again. I m Very bloated, have lower stomach ache like a burning feeling after the bowel movements. In 2018 i did a.colonoscopy all clear and 9 months ago got stool tested for blood all clear. I m worried they have missed something as the itching won t stop and blood happens every now and then. I m on thyroxine, and have thalassemia so low iron but the stomach pain has resurfaced .