An article published in the Journal Watch Gastroenterology today outlined the increased risk that people with Crohn's face in regards to deep vein trombosis, or blood clots. The following is the summary of this article that you can read in its entirety at
http://gastroenterology.jwatch.org/cgi/content/full/2010/1008/1?q=featured_jg
"This study indicates that patients with IBD who suffer an unprovoked episode of VTE can be informed that they have approximately a one in three chance of recurrence within 5 years. The decision to institute chronic anticoagulation in these patients is complex and depends on several factors, including results from standard work-ups for associated hypercoagulability and current level of disease activity. Obviously, the risk for either hemorrhage or exacerbation of chronic anemia associated with anticoagulation is a complicating factor in the decision."