Severe constipation x4 yrs, had colonoscopy. Since the scope 2 weeks ago, I have felt worse GI wise. I know have more urgent and loose stools with more pain, nausea and discomfort. Looking for crohns. Why would I have such a change after a scope?

Post colonoscopy. I agree with Dr. D about waiting for biopsy results and going on a fodmap diet. Anecdotally. I had 2 such cases. One patient was felt to have had an adverse reaction to detergents used in cleansing the scope. The other developed a condition called lymphocytic colitis which responded to oral corticosteroid treatment.
Results. best to await the biopsy results - that'll advise you on the way forward. In the interim, consider consulting a dietician specialising in irritable bowel syndrome.