Evidence-based medicine (EBM) plays a key role for decision making in clinical practice. Clinicians are encouraged to adhere to treatment guidelines based on high quality clinical trials, systematic reviews and meta-analyses, that are the focus of the Cochrane Collaboration. EBM is not, however, a panacea for medical decision making. The results of randomized clinical trials apply to populations of patients, and the challenge is to translate the results to individuals. Individual patients require different thought processes because presentation and response vary, and external factors (e.g. patient preference) influence the choice of treatment. The application of EBM demands clinical judgement. The case of a 28 year old scientist who presented with typical features of moderate ulcerative colitis, illustrates the dilemma. At each stage of his illness the treatment options based on EBM were discussed, including high dose 5-aminosalicyclic acid with or without topical therapy, corticosteroids, infliximab, immunomodulation, complementary therapy and surgery. Ultimately, therapeutic decisions depended on the patient's circumstances, preferences and response. Decisions should avoid circular motion caused by the illusion of progress and always consider the direction of travel.