Each time I have any illness- my PD significantly worsens--if I take antibiotics--especially if I have nausea-ands diarrhea- again-its as if i am taking almost no sinemet. When I look for a cause/effect discussion or even an anecdote similar to mine- I find little. Am I just making myself worse (reverse-placebo effect) or have other people experienced this? Since the bulk of the absorption of l-dopa fro the go tract is seen in the small bowel- it seems to make sense that antibiotic-associated diarrhea might affect absorption directly or transit time.