Chapter 37: Disorders of Gastrointestinal Function

Disorders of pelvic floor support and continence are addressed through therapeutic approaches such as pelvic floor muscle training, which targets the underlying weakness contributing to stress-related urinary leakage. The chapter explores inflammatory bowel conditions, particularly Crohn disease, emphasizing modern immunosuppressive treatment strategies including monoclonal antibody therapies that suppress tumor necrosis factor signaling to reduce chronic mucosal inflammation and tissue damage. Peptic ulcer disease represents a major category of gastric and duodenal pathology, with emphasis on nonsteroidal anti-inflammatory drug-induced mechanisms of mucosal injury as a primary etiology alongside infectious causes. Hypersecretory disorders receive significant attention, with particular focus on Zollinger-Ellison syndrome, a rare neuroendocrine malignancy characterized by gastrin-secreting tumors that drive excessive gastric acid production and refractory ulceration. The chapter integrates discussion of acid-suppressive pharmacotherapy and the diagnostic approaches used to identify these conditions. Throughout, the content emphasizes the relationship between underlying pathophysiologic mechanisms and clinical manifestations, demonstrating how understanding the biochemical and cellular basis of gastrointestinal dysfunction informs treatment selection and patient outcomes across multiple disease categories affecting different regions and functional systems of the digestive tract.