Author(s): Marilia Carabotti [*] 4 , Carola Severi 1 , Frida Leonetti 2 , Francesco De Angelis 3 , Olga Iorio 3 , Enrico Corazziari 1 , Gianfranco Silecchia 3
bariatric surgery; gastroesophageal reflux disease; gastrointestinal motility; obesity; upper gastrointestinal disorders
In previous years, morbid obesity has become an epidemic condition and worldwide its incidence has more than doubled since 1980. In 2008, more than 1.4 billion adults aged 20 years and older were overweight. Of these, more than 200 million men and nearly 300 million women were obese  . This alarming situation leads to a significant rise in healthcare costs due to obesity-related, chronic medical conditions such as hypertension, diabetes, dyslipidemia, sleep apnea and cardiovascular diseases. Furthermore, obesity represents a risk factor for the development of benign and malign gastrointestinal (GI) conditions such as nonalcoholic fatty liver disease  , cholelithiasis  , severe acute pancreatitis  , complicated diverticular disease  , colorectal adenoma  , GI cancers  and gastroesophageal reflux disease (GERD)  . Recently, a higher prevalence of several other functional upper digestive disorders has emerged. By means of a standard questionnaire based on Rome Criteria, Fysekidis et al . analyzed 120 consecutive patients who were candidates for bariatric surgery and reported that 89% of patients complained of functional symptoms; in particular, 31% esophageal and 38% gastroduodenal symptoms  . The frequency of functional GI disorders attributed to the gastroduodenal regions is higher than that for the distal regions, even if their overall prevalence has not been studied in detail. Owing to their chronic course, these disorders have a bearing on public spending and their correct diagnosis would avoid unnecessary cost-consuming investigations. The objective of this review was to analyze this topic in a unified manner, with an attempt to analyze the pathophysiological mechanisms involved, and to compare the presence of upper GI symptoms in obese patients before and after bariatric surgery in order to understand why and how surgery may change a patient's clinical assessment.
Upper GI symptoms in obese patients
Heartburn & regurgitation
Heartburn and regurgitation are the characteristic symptoms of the typical reflux syndrome, which can be diagnosed on a clinical basis without further diagnostic testing  . In the available literature, these two symptoms have often been considered together as GERD. In general, GERD is a common condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications. In the USA, 20-30% of the general population refers troublesome heartburn and regurgitation, with an annual cost for proton pump inhibitor (PPI) treatment of US$10 billion  . A strong correlation between obesity and GERD has been demonstrated.
The prevalence of GERD is higher in obese patients compared with normal weight controls, with an increased risk of 2.5 of developing symptoms and erosive esophagitis  . This is most likely related to increased esophageal acid exposure  . On the basis of the evidence of upper GI endoscopy and 24-h pH-metry, Fornari et al . showed that obese patients have higher prevalence of erosive disease and a lower frequency of nonerosive and functional heartburn with respect to a normal-weight control...