The relationship between Microscopic Colitis and Inflammatory Bowel Disease is unclear. However, when both are diagnosed they seem to be part of a broader spectrum of the same disease, more than just a coincidence. We report a 55 years old woman with Ulcerative Colitis limited to the rectum with complete clinical and endoscopic response to standard treatment and adequate surveillance for 13 years, who abandoned treatment and control. After eight years, she consulted for mild-to-moderate non-bloody diarrhea lasting several months. Colonoscopy and basic laboratory did not show any alterations. Nevertheless, random biopsies had a characteristically pattern compatible with Lymphocytic Colitis. After the first week of treatment with budesonide the patient was asymptomatic and still in clinical remission, with negative fecal calprotectin at 6 months’ follow-up.The relationship between Microscopic Colitis and Inflammatory Bowel Disease is unclear. However, when both are diagnosed they seem to be part of a broader spectrum of the same disease, more than just a coincidence. We report a 55 years old woman with Ulcerative Colitis limited to the rectum with complete clinical and endoscopic response to standard treatment and adequate surveillance for 13 years, who abandoned treatment and control. After eight years, she consulted for mild-to-moderate non-bloody diarrhea lasting several months. Colonoscopy and basic laboratory did not show any alterations. Nevertheless, random biopsies had a characteristically pattern compatible with Lymphocytic Colitis. After the first week of treatment with budesonide the patient was asymptomatic and still in clinical remission, with negative fecal calprotectin at 6 months’ follow-up.