The estimated prevalence of gastritis in the general US population is approximately 50%. Patients with gastrointestinal disease often present to the primary care practitioner with dyspepsia and abdominal pain. Osteopathic palpatory evaluation suggests that there is an association among gastrointestinal disease, the presence of posterior midthoracic pain, and chronic headache. On the basis of findings from a review of the literature, the author assesses the potential etiologic mechanisms of this clinical association. Possible mechanisms include the physiologic function of the vagus nerve, a neural convergence model, and the inherent properties of Helicobacter pylori. To demonstrate the clinical significance of these mechanisms, the author presents the case of a 30-year-old woman with headache, thoracic discomfort, and gastritis associated with H pylori infection. The author suggests that successful treatment of patients with gastrointestinal disease includes osteopathic manipulative treatment, behavioral modification, and pharmacotherapy, even when challenged by antibiotic resistance.