[Accurate predictors for acute diverticulitis].

In a relatively high percentage of patients with a clinically suspected diverticulitis a different diagnosis is established after imaging tests, such as 'appendicitis' or 'intestinal obstruction'. The clinical diagnosis 'acute diverticulitis' is correct for between 43% and 68% of suspected patients. Strongly predictive variables for the diagnosis are tenderness in the left lower abdomen only, CRP > 50 mg/l and absence of vomiting. This triad has a positive predictive value of 97% (95% CI: 83-99) for the final diagnosis 'diverticulitis'. The negative predictive value is much lower, namely 47%: the absence of 1 of the 3 factors does not (sufficiently) exclude 'diverticulitis'. This triad can be an easy-to-use decision rule to rule in diverticulitis.