I suffered the same history as you. Lifelong bowel problems that plagued me until a volvulus caused me to have a right hemicolectomy with removal of the ileocecal valve in 2015. My quality of life deteriorated and I became more and more ill. Chronic diarrhea, abdominal pain, bone pain, muscle weakness and ternderness, and brain fog. In the last 6 months I have had so much blood work with nothing showing up positive. Finally my PCP referred me to a gastroenterologist that read my surgery history and labs and colitis on CT and said you have bacterial overgrowth due to your hemicolectomy with ileocecal valve removal. I have been on 3 different antibiotics. When I am on them I get better but when the course of antibiotic is finished the diarrhea returns.
I just met my gastroenterologist last week. I see him in 4 weeks to determine what course to take from there. He said patients with SIBO usually remain on treatment the rest of their lives.