Global Gastrointestinal Drugs Market Assessment, By Drug Type [Branded, Generic], By Drug Class [Biologics, Proton Pump Inhibitors, Aminosalicylates, Antacids, Laxatives, H2 Antagonists, Others], By Route of Administration [Oral, Parenteral, Rectal], By Application [Ulcerative Colitis, Irritable Bowel Syndrome, Crohn's Disease, Celiac Disease, Gastroenteritis, Others], By Distribution Channel [Hospital Pharmacies, Retail Pharmacies, Online Pharmacies], By Region, Opportunities and Forecast, 2017-2031F