There are two ways that microbubbles might contribute to a strong signal in areas of inflammation in the small intestine or colon. The first is directly through neoangiogenesis and the increase in blood flow to the site. Defined as the growth of new blood vessels, neoangiogenesis is important to the pathogenesis of both Crohn's disease and ulcerative colitis. An expanded microvascular bed in the mucosa and submucosa of IBD patients with active inflammation has been confirmed, and is consistent with the high levels of integrins characteristic for proliferating endothelium (e.g. IL-8, bFGF, and VEGF) found in the microvessels of tissue affected by IBD. The hope is that the increased blood flow in actively inflamed IBD will be correlated with a stronger US signal from the increased concentration of MB flowing through the site.