Symptoms related to functional and sensory abnormalities are frequently encountered in patients with diabetes mellitus. Most symptoms are associated with impaired gastric and intestinal function. In this review, we discuss basic concepts of sensory-motor dysfunction and how they relate to clinical findings and gastrointestinal abnormalities that are commonly seen in diabetes. In addition, we review techniques that are available for investigating the autonomic nervous system, neuroimaging and neurophysiology of sensory-motor function. Such technological advances, while not readily available in the clinical setting, may facilitate stratification and individualization of therapy in diabetic patients in the future. Unraveling the structural, mechanical, and sensory remodeling in diabetes disease is based on a multidisciplinary approach that can bridge the knowledge from a variety of scientific disciplines. The final goal is to increase the understanding of the damage to GI structures and to sensory processing of symptoms, in order to assist clinicians with developing an optimal mechanics based treatment.

Functional gastroduodenal disorders are chronic, heterogeneous conditions experienced by adults worldwide. The Rome III consensus recognizes four syndromes: functional dyspepsia, belching disorders, nausea and vomiting disorders and ruminating syndrome. Considerable advances have occurred in the field of functional gastroduodenal disorders. This review provides an overview of the definitions, epidemiology, clinical features, investigations and treatments of some of these disorders. Functional dyspepsia is divided into post-prandial distress syndrome (PDS) and epigastric pain syndrome (EPS). The prevalence of functional dyspepsia is about 11–20% in the western world. Dysfunctional gastrointestinal motility and hypersensitivity are involved in the generation of symptoms in some patients. Several classes of drugs are used to treat patients with functional dyspepsia, and the increasing understanding of pathophysiology will greatly affect future treatment regimens. Belching disorders may have either a behavioural or a physiological background, and therefore behavioural and speech therapies show promise, but definitive studies are required. The effect of fundoplication and drugs, such as a selective gamma-aminobutyric acid agonist baclofen, on belching await confirmatory studies on their usefulness. Mechanisms of functional nausea and vomiting are poorly understood, and their treatment currently focuses on pharmacological and non-pharmacological therapies, including antidepressants and psychological approaches.