Microscopic colitis (MC) is a chronic inflammation condition of the colon characterized by watery diarrhea and normal appearing mucosa. A 75-year-old female presented with one-year history of chronic diarrhea while taking cannabidiol (CBD) for pain. Colonoscopy with random colon biopsies revealed collagenous colitis. She started budesonide and stopped CBD. At six-week follow-up, her diarrhea improved, and the budesonide dose was decreased. She restarted CBD oil twice but had diarrhea both times. Her diarrhea resolved after taking budesonide and stopping CBD. We report a case of CBD-associated MC to make clinicians aware of this potential adverse effect in patients who chronically use CBD.