BACKGROUND: Many patients with microscopic colitis (MC) also suffer from symptoms of irritable bowel syndrome (IBS), but the only treatment given is corticosteroids for the diarrhoea. The aim of this study was to examine how social factors, life style factors and drug treatment affect symptoms and well-being in patients suffering from MC. METHODS: Women, over the age of 73years, with biopsy-verified MC, at any Departments of Gastroenterology, Skåne, between 2002 and 2010 were invited. The questionnaires Gastrointestinal Symptom Rating Scale (GSRS) and Psychological General Well-being Index (PGWB) were sent by mail, along with questions about social and life style factors, and medical history. RESULTS: Of 240 invited, 158 patients (66%) were included (median age 63years, range 27-73years). Only 26% had never smoked. Smoking and concomitant IBS were associated with both impaired gastrointestinal symptoms (OR=3.96, 95% CI=1.47-10.66 and OR=4.40, 95% CI=2.09-9.26, respectively) and impaired psychological well-being (OR=2.77, 95% CI=1.04-7.34 and OR=3.82, 95% CI=1.83-7.99, respectively). Treatment with proton pump inhibitors (PPI) was associated with increased gastrointestinal symptoms (OR=3.44, 95% CI=1.45-8.16). Age, social factors, and corticosteroids had no effect on symptoms or well-being. Smoking was the only risk factor associated with IBS (OR=2.68, 95% CI=1.115-6.26). CONCLUSION: Smoking and IBS are associated with impaired gastrointestinal symptoms and psychological well-being in MC patients. PPI is associated with impaired gastrointestinal symptoms.