INTRODUCTION:Outcomes and safety of budesonide maintenance therapy in microscopic colitis (MC) are not well known.METHODS:Adult residents of Olmsted County, Minnesota, diagnosed with MC (2002–2019) and treated with budesonide were identified using the Rochester Epidemiology Project. Response was assessed at 12 ± 4 weeks after initiation of therapy and defined as complete (resolution of diarrhea), partial (≥50% improvement in the number of bowel movements), nonresponse (<50% improvement), and intolerance (discontinued because of side effects). For safety outcomes, cases (budesonide maintenance) and MC controls (no budesonide therapy) were matched by sex and age at diagnosis (±2 years).RESULTS:A total of 450 patients were identified, of whom 162 (36.0%) were treated with budesonide for induction of clinical remission (median age 67 [23–91] years and 126 women [77.8%] ). Clinical outcomes for induction were as follows: 130 (80.2%) complete response, 22 (13.6%) partial response, 8 (4.9%) no response, and 2 (1.2%) intolerance. After induction, 96 (63.2%) had recurrence after discontinuation, of whom 27 (28.1%) required further budesonide induction treatment without maintenance, 56 (58.3%) required long-term budesonide maintenance, and 13 (13.5%) were treated with other therapies. Of those receiving budesonide maintenance, all responded (55 [98.2%] complete and 1 [1.8%] partial). No patient stopped maintenance from adverse events. The median duration of follow-up was 5.6 years (0.3–18.9). There was no significant difference between cases and controls in the incidence of osteopenia/osteoporosis, diabetes mellitus, hypertension, glaucoma, or cataracts.DISCUSSION:The long-term use of budesonide in MC seems to be effective and generally well tolerated with limited adverse effects.