I opened this thread for all discussions about low intestinal blood flow: measurement, causes, consequences, current research. Interesting questions such as: which levels of low blood flow actually cause which problems blood flow measurements are notoriously inexact. measuring hypoxia can help: measurement of hypoxia-related cytokines: PGE2, IL-8, VEGF manometry: measurement of ph in the gut. they do this in ICU patients to monitor hypoxia. treatments current research directions connections to CFS Regarding CFS, this connects in several ways: low intestinal blood flow can cause low oxygen levels which facilitates growth of anaerobic bacteria in the small intestine. depending on the species involved this has been linked to cfs (see e.g. Meirleir). It connects in some people to POTS: in healthy people, when standing up, blood flow in the superior mesenteric artery remains the same as when laying. this is thanks to a compensation mechanism. In illness it can diminish, creating hypoxia I have quite some research papers on this, if you need some just ask!