Microscopic colitis is an inflammatory bowel disease (IBD) that leads to chronic, watery diarrhoea. First believed to be rare, microscopic colitis has received more attention in recent decades, resulting in increasing incidence rates that exceed those of classic IBD in some countries. Hopefully, it is common practice nowadays to refer patients with chronic diarrhoea for a colonoscopy with biopsy samples taken, as this is the only way to diagnose microscopic colitis. Histology results distinguish between the subtypes of microscopic colitis — lymphocytic colitis, collagenous colitis and the more recently introduced incomplete microscopic colitis.  The cardinal symptom of watery diarrhoea eventually results in severe urgency and faecal incontinence. Furthermore, many patients experience abdominal pain that can be misinterpreted as diarrhoea-predominant irritable bowel syndrome (IBS-D), resulting in inadequate treatment. Microscopic colitis is a benign condition but it can severely impact quality of life. Fortunately, there is effective treatment with budesonide, a locally active steroid, and thiopurines or biologics can be tried for budesonide-refractory disease. The mistakes discussed here are derived from observations of the accepted view of microscopic colitis, but also reflect the many misconceptions I’ve encountered during lectures given throughout Europe. There is still a lack of awareness and knowledge when it comes to microscopic colitis compared with the other IBDs and avoiding these mistakes will alleviate unnecessary suffering and improve patient care. Recently, UEG and the European Microscopic Colitis Group (EMCG) have published clinical guidelines to improve the diagnosis and treatment of microscopic colitis.1 The statements and recommendations, evidence based or expert-group consensus, are used as the backbone for tackling these mistakes and are backed up by my own clinical experience