Diverticulitis is a common disease which, in the Netherlands, leads to approximately 13,500 hospitalizations annually. This figure represents merely 12% of actual cases encountered by general practitioners. The combined factors of older age, pain in the left lower abdomen which increases on movement, an elevated C-reactive protein level, the absence of vomiting and a prior episode of diverticulitis are highly predictive for this clinical diagnosis. This prediction model has been developed in secondary care centres. Its diagnostic value has yet to be proven in general practice.