Background: The aim of the study was to evaluate the diagnostic role of Kruis score and intestinal ultrasound in young patients with abdominal pain and bowel dysfunction.
Methods: Prospective, double blind, case-control study in 297 consecutive patients with Crohn's disease and irritable bowel syndrome (from 1993 to 1995).
Inclusion criteria: abdominal pain, bowel dysfunction without clear symptoms or signs of organic disease. The final diagnosis is obtained with usual diagnostic criteria and confirmed by at least 2 years of follow-up. Intestinal ultrasound is considered diagnostic of Crohn's disease if bowel wall thickness is = or > 7 mm; the Kruis score is diagnostic for irritable bowel syndrome if = or > 44.
Results: To diagnose Crohn's disease, intestinal ultrasound and Kruis score respectively showed sensitivity of 84 and 97%, specificity of 98 and 50%, positive predictive value of 91 and 33%, negative predictive value of 96 and 98%, efficacy of 95 and 60%. Both exams suggest the same diagnosis in 55% of patients with a correct diagnosis of 97%.
Conclusions: The intestinal ultrasound and the Kruis score can be a good diagnostic association in young patients with abdominal pain and bowel dysfunction but without clear symptoms or signs of organic disease. If their diagnostic conclusions are the same (55%), they have a low probability of diagnostic error (3%). If they show a different diagnostic hypothesis, other markers of disease, for example ASCA, can be used.