Injury of the gastrointestinal tract in Schönlein-Henoch disease is one of the most serious potential conditions. Common potential risks of serious late complications are: small bowel perforation, intussusception, gastro-intestinal bleeding and others. Ultrasound diagnosis is effective as first-line screening method in children with an abdominal form of the disease (gastrointestinal symptoms). In the present clinical observation, we present three clinical cases of children with Schönlein-Henoch-abdominal form, in which we studied the new aspects of the changes in the coagulation system, as well as the monitoring of abdominal involvement by ultrasound examination of the small intestines. The results of the ultrasound examination in these patients gives grounds for non-maintenance of the universal treatment with corticosteroids. The study in the dynamics of factor XIII and von Willebrand factor are convincingly informative about the degree of vascular damage and disease activity.