You can easily search a majority of the Penn Libraries journal titles about Gastroenterology in Browzine.
Gastroenterology — Medical Specialties A-N — University of Pennsylvania — BrowZine
Digestive System Disorders — Diseases — University of Pennsylvania — BrowZine
Below are direct links to a selection of these titles.
Clinical Pancreatology for Practising Gastroenterologists and Surgeons by 
Sex/gender-specific medicine in the gastrointestinal diseases by 
Imaging Diagnostics in Pancreatic Cancer: A Clinical Guide by 
Inflammatory bowel disease : pathogenesis, diagnosis and management by 
Practical gastrointestinal pathology : frequently asked questions by 
The Washington Manual Gastroenterology Subspecialty Consult by 
Coloproctology : Colon, Rectum and Anus: Anatomic, Physiologic and Diagnostic Bases for Disease Management by 
Gastrointestinal Cancer: A comprehensive guide to diagnosis and management by 
