This issue of Surgical Pathology Clinics, edited by Rhonda K. Yantiss, will focus on Gastrointestinal Pathology: Common Questions and Diagnostic Dilemmas. Topics in this issue include, but are not limited to: Other forms of esophagitis; Diagnosis and management of Barrett-related neoplasia in the modern era; Patterns of gastric injury; Practical approach to the flat duodenal biopsy specimen; Chronic colitis in biopsy samples; Mucosal biopsy following bone marrow transplantation; The many faces of medication-related injury in the GI tract; The differential diagnosis of acute colitis: Clues to a specific diagnosis; Problematic colorectal polyps; Persistent problems in colorectal cancer reporting; Emerging concepts in gastric neoplasia; Immunohistochemistry pitfalls; Molecular testing in the modern era, and Lymphoproliferative diseases of the gut.