Chapter 17. Functional (Nonulcer) Dyspepsia

• Dyspepsia is a common symptom having either an organic or a functional cause; distinguishing between the two can be a challenge.
• Clinical features of functional dyspepsia, gastroesophageal reflux disease, and gastrointestinal motility disorders overlap, making diagnosis difficult.
• Most patients with functional dyspepsia have normal esophagogastroduodenoscopy (EGD) findings.
• Endoscopy is indicated for patients with new-onset symptoms who are >55 years of age or have alarm features.
• Functional dyspepsia remains a diagnosis of exclusion.

This chapter outlines the evaluation and management of dyspepsia, with a primary focus on functional dyspepsia, also interchangeably called nonulcer dyspepsia. The term dyspepsia derives from the Greek "dys," meaning bad, and "pepsis," meaning digestion. Dyspepsia is a symptom, not a diagnosis. The term encompasses a broad spectrum of symptoms that include upper abdominal pain or discomfort, bloating, early satiety, postprandial fullness, nausea with or without vomiting, anorexia, symptoms of gastroesophageal reflux disease (GERD), regurgitation, and belching.

Classification

The multiple causes of dyspepsia can be classified as organic or functional. Among the organic causes are esophagitis, gastritis, peptic ulcer disease, benign esophageal strictures, upper gastrointestinal malignancies, chronic intestinal ischemia, and pancreaticobiliary disease. In addition, several medications can cause dyspeptic symptoms (Table 17–1). Most notable are nonsteroidal anti-inflammatory drugs (NSAIDs), which can cause mucosal injury leading to gastritis. Functional dyspepsia excludes all organic causes.

Previously, the Rome II criteria defined functional dyspepsia as pain centered in the upper abdomen in the setting of a normal endoscopy, with three main subtypes: ulcer-like, dysmotility-like, and unspecified (nonspecific). Recognizing that patients with functional dyspepsia may present with epigastric symptoms other than pain, the revised Rome III criteria in 2006 added bothersome postprandial fullness, early satiation, and epigastric burning to the diagnostic criteria (Table 17–2). Therefore, functional dyspepsia is now defined as "the presence of symptoms thought to originate from the gastroduodenal region, in the absence of any organic, systemic, or metabolic disease that is likely to explain the symptoms." In addition, the prior subtypes were revised to improve their clinical utility. Per Rome III criteria, functional dyspepsia symptoms fall into two main, distinctively defined disorders: postprandial distress syndrome and epigastric pain syndrome. Postprandial distress syndrome includes bloating, fullness, or early satiety with meals, while epigastric pain syndrome is defined by focal burning or pain localized to the epigastric region not relating to gallbladder or biliary causes. Postprandial distress syndrome and epigastric pain syndrome may coexist in patients with functional dyspepsia.