Definition, Pathogenesis, and Management of That Cursed Dyspepsia

Abstract

Dyspepsia is an umbrella term used to encompass a number of symptoms thought to originate from the upper gastrointestinal tract. These symptoms are relatively nonspecific; not surprisingly, therefore, a myriad of conditions may present with any one or a combination of these symptoms. Therein lays the clinician's first challenge: detecting the minority who may have a potentially life-threatening disorder, such as gastric cancer, from a population whose symptoms are, for the most part, considered functional in origin. The second challenge lies in the definition and management of those individuals with functional dyspepsia (FD); the major focus of this review. The Rome process has addressed the issue of FD definition and a look back at the evolution of Rome criteria for this disorder illustrates the complexities that have so frustrated us. There has been no shortage of hypotheses to explain symptom pathogenesis in FD; initially focused on gastric sensorimotor dysfunction, these have now strayed well into the duodenum and have come to entertain such factors as immune responses and the microbiome. FD has proven to be an equally challenging area for therapeutics; while the staple approaches of acid suppression and eradication of Helicobacter pylori have some limited efficacy in select populations, strategies to ameliorate symptoms in the majority of sufferers based on presumed pathophysiology have largely foundered. Lacking a validated biomarker(s) FD continues to be an elusive target and is likely to remain so until we can better define the various phenotypes that it must surely contain.

Relationship between symptoms during a gastric emptying study and intestinal chemosensitivity with daily symptoms

“…30 The symptoms during a GE study may be explained by abnormal GE, decreased gastric accommodation, and increased gastric sensitivity. 1 In this study, the symptoms during the GE study and during duodenal lipid infusion were correlated, which suggests that the small intestine may also contribute to symptoms during a GE study. We previously observed that 58% of dyspeptic patients had moderately severe or more intense symptoms during duodenal lipid infusion.…”

“…32 Gastric accommodation and sensitivity were not assessed. 1 In summary, severe symptoms during the GE scintigraphy explained respectively 62% and 40% of the variance in daily symptom severity and QOL in NUD. The symptoms during a GE study may provide a biomarker of NUD.…”

“…Symptoms were evaluated with NDI and GCSI instruments that evaluate similar symptoms as the Leuven Postprandial Distress Scale . Gastric accommodation and sensitivity were not assessed …”

“…Non‐ulcer dyspepsia (NUD), which affects between 5% and 11% of the adult population, is defined by upper gastrointestinal symptoms, often related to eating . Between 20% and 50% of patients with NUD have abnormal, often delayed, gastric emptying (GE) .…”

“…Non‐ulcer dyspepsia is associated with abnormal gastric emptying, impaired gastric accommodation, increased gastric sensitivity, and increased enteral chemosensitivity. Approximately 60% of NUD patients but only 10% of healthy controls reported moderate, severe, or intolerable symptoms, suggestive of increased enteral chemosensitivity, during duodenal carbohydrate and lipid infusions (300 kcal) .…”