infection started from probiotics/antibiotics that caused mucous nausea and blood. What test should I get for this infection. Already had colonoscopy, hpylori, celiac, lactose, parasite, blood test ultasound had this 2 years, getting better over time?

Colitis. It sound like you had C.difficle colitis, if you are treated appropriately and improving clinically, no additional test is required.
Disordered bowel. it looks like your doctors have done a nice work upBecause no specific problems have been found, and your symptoms persist, the answer may lie in a food intolerance or stress being carried in the bowel. Generally, blood does signify more significant inflammation, such as Crohn's disease-Colonoscopy should see this. As a next step, I would As a next step, consider consultation with a dietician .