A comparison of rectal and esophageal sensitivity in women with functional heartburn

Functional gastrointestinal disorders (FGIDs) such as functional heartburn have been diagnosed based on the symptomatic organ. Overlapping symptoms in other areas of the gastrointestinal tract outside the symptomatic organ have been reported. Visceral hypersensitivity is one explanation for symptoms of FGIDs; however whether it is organ-specific or involves the entire gastrointestinal tract is unclear. People with functional heartburn have been found to have symptoms of visceral hypersensitivity in the lower gastrointestinal tract including abdominal cramping, bloating, and nausea concurrently with symptoms in the upper gastrointestinal tract in response to balloon distention of the esophagus. Yet, no studies were found that document whether or not there is an overlap between esophageal and rectal sensitivity in the same patient. In order to provide a comprehensive treatment plan for patients, attention to symptoms throughout the gastrointestinal tract is needed to understand and manage patient care. Therapeutic plans that are symptom specific may fail to provide patients with global relief of symptoms. Therefore, the purpose of this study was to document visceral hypersensitivity as a key to the pathophysiology of FGIDs. The central hypothesis was to examine if there is a fundamental alteration in visceral sensitivity that links the FGIDs. The primary aim was to compare visceral sensitivity in two areas of the gastrointestinal tract in a functional heartburn group with each subject serving as their own control. This descriptive study explored the relationship of visceral sensitivity in the esophagus and rectum of functional heartburn patients with known esophageal hypersensitivity. Fourteen women with functional heartburn participated in this study. Each participant underwent a training balloon session (Visit 1). During Visit 1, balloon distention of the esophagus and rectum was performed using the electronic barostat. Within 7-14 days of Visit 1, participants reported back to the study center for the data collection visit which included repeat distention studies (Visit 2). The primary endpoint was the balloon volume and pressure measurements at maximum pain threshold (MPT). Participants rated symptom severity for initial perception threshold (IPT), pain threshold (PT), and maximum pain threshold (MPT) on a 100 mm visual analog pain scale with both esophageal and rectal barostat balloon inflation. The barostat controlled either pressure or volume while recording the other variable. Multiple data points were analyzed to assess the relationship of sensation and pain to volume, pressure, and organ compliance. After the barostat study on Visit 2, the participants were asked to fill out the Functional Digestive Disorder Quality of Life Scale (FDDQL) on the severity of gastrointestinal symptoms. The findings revealed a positive correlation for the relationship of rectal and esophageal volume scores (r = .6, p = .02) and pressure scores (r = .53, p = .05) to first pain (PT). These findings demonstrated that visceral sensitivity may occur in two separate areas of the gastrointestinal tract simultaneously. These findings may have the potential to impact the clinical understanding of the clinical syndrome, illness behavior, and influence treatment efficacy.