Coagulation system and inflammatory bowel disease: Therapeutic and pathophysiologic implications

Several observations are compatible with an association between an haemostatic imbalance and the pathogenesis of inflammatory bowel disease. The prothrombotic state in Crohn's disease and ulcerative colitis is probably not simply the cause of an increased susceptibility for thrombembolic complications, but might also reflect an important element of the pathogenetic changes observed in the small vessels of the intestinal wall. However, it is still unclear whether alterations in the coagulation system are the cause or the aftermath of the systemic inflammatory response observed in inflammatory bowel disease. Several recent observations describe therapeutic efficacy of unfractioned or low-molecular weight heparin in patients with active ulcerative colitis and Crohn's disease. Based on these clinical observations new concepts concerning the pathophysiology of inflammatory bowel disease have emerged.