The global prevalence of diabetes mellitus is increasing; arguably as a consequence of changes in diet, lifestyle and the trend towards urbanization. Unsurprisingly, the incidence of both micro and macrovascular complications of diabetes mirrors this increasing prevalence. Amongst the complications with the highest symptom burden, yet frequently under-diagnosed and sub-optimally treated, is diabetic autonomic neuropathy, itself potentially resulting in cardiovascular autonomic neuropathy and gastrointestinal (GI) tract dysmotility. The aims of this review are fourfold. Firstly to provide an overview of the pathophysiological processes that cause diabetic autonomic neuropathy. Secondly, to discuss both the established and emerging cardiometric methods for evaluating autonomic nervous system function in vivo. Thirdly, to examine the tools for assessing pan-GI and segmental motility and finally, we will provide the reader with a summary of putative non-invasive biomarkers that provide a pathophysiological link between low-grade neuro inflammation and diabetes, which may allow earlier diagnosis and intervention, which in future may improve patient outcomes.