Welcome to Silicon Valley Gastroenterology

Dr. Andrew Roorda is Board Certified in Internal Medicine and Gastroenterology by the American Board of Gastroenterology and an Adjunct Clinical Assistant Professor at the Division of Gastroenterology and Hepatology, Stanford University School of Medicine. He has published 23 articles in various scientific journals including the New England Journal of Medicine, Gastrointestinal Endoscopy, Digestive Diseases and Sciences and Practical Gastroenterology. 

2004 - Doctor of Medicine, St. George's University School of Medicine, Grenada, West Indies

1997 - Certificate of Completion, Post-Baccalaureate Pre-Medical Program, Duquesne University, Pittsburgh, PA

1995 - B.A. History, University of California, San Diego, La Jolla, CA

2008-2011: Clinical Fellow in Gastroenterology, West Virginia University School of Medicine, West Virginia University Hospitals, Ruby Memorial Hospital, Morgantown, WV

2006-2008: Resident in Internal Medicine, St. Mary's Medical Center, San Francisco, CA

2008-2011: Intern in Internal Medicine, St. Mary's Medical Center, San Francisco, CA

PUBLICATIONS:

1. Rider JA, Roorda AK, RIder DL. An analysis of standards for antacid simethicone defoaming properties. Gastroenterology 1995; 108:A32.

2. Rider JA, Roorda AK, Rider DL. Further analysis of standards for antacid simethicone defoaming properties. Curr Ther Res Clin E 1997;58:955-63. 

3. Roorda AK, Hansen JP, Rider JA, Huang S, Rider DL. Ectopic breast cancer: special treatment considerations in the postmenopausal patient. Breast J 2002;8:286-9. 

4. Rider DL, Rider JA, Roorda AK. PEG: A safe procedure in the elderly including the oldest old. Pract Gastroenterol 2002;XXVI:38-44. 

5. Zellner C, Roorda AK. A bleeding Meckel's diverticulum. New Engl J Med 2003;349:E9-E. 

6. Wise GJ, Roorda AK, Kalter R. Male breast disease. J Am Coll Surgeons 2005;200:255-69. 

7. Roorda AK, Rider DL, Rider JA, Conroy BF. Do pH and temperature play a role in gastrostomy tube deterioration? Jpen-Parenter Enter 2005;29:388-91. 

8. Roorda AK, Marcus SN, Triadafilopoulos G. Early experience with radiofrequency energy ablation therapy for Barrett's esophagus with and without dysplasia. Dis Esophagus 2007;20:516-22. 

9. Roorda AK, Triadafilopoulos G. Circumferential and focal radiofrequency ablation for the treatment of Barrett's esophagus. Expert Rev Gastroenterol Hepatol 2008;2:627-34. 

10. Arora G, Basra S, Roorda AK, Triadafilopoulos G. Radiofrequency ablation of Barrett's esophagus. Eur Surg 2009;41:19-25. 

11. Roorda AK. Introduction to a new series. Endoscopy: opening new eyes. Pract Gastroenterol 2009;XXXIII:13-4. 

12. Roorda AK, Kupec JT, Sundaram U. I spy biliary and pancreatic ducts: the spyglass single operator peroral cholangiopancreatoscopy system. Endoscopy: opening new eyes, series #1. Pract Gastroenterol 2009;XXXIII:15-32. 13. Roorda AK, Triadafilopoulos G.

13. Roorda AK, Triadafilopoulos G. A fellow’s guide to generating the endoscopy procedure report. Gastrointest Endosc 2010;72:803-805. 

14. Roorda AK, Kupec JT, Ostrinsky Y, Shamma'a JM, Goebel SU, Sundaram U. Endoscopic approaches to capsule endoscopy retention. Expert Rev Gastroenterol Hepatol 2010;4:713-721. 

15. Roorda AK, Marcus SN, Triadafilopoulos G. Algorithmic approach to patients presenting with heartburn and epigastric pain refractory to empiric proton pump inhibitor therapy. Dig Dis Sci 2011;56(10):2871-8.

16. Kupec JT, Roorda AK, Williams HJ, Goebel SU. Recurrent hematochezia secondary to gastrointestinal stromal tumors (GISTs) in neurofibromatosis type one. WV Med J 2011 JulyAug;107(4):16-19. 

17. Jalali F, Roorda AK, Sundaram U. Biliary stone extraction techniques: old and new. Pract Gastroenterol 2011;XXXV:17-46. Endoscopy: opening new eyes, series #6. 

18. Triadafilopoulos G, Roorda, AK, Akiyama J. Update on foreign bodies in the esophagus: diagnosis and management. Curr Gastroenterol Rep 2013;15(4):317. 

19. Triadafilopoulos G, Roorda AK, Akiyama J. Indications and safety of proton pump inhibitor drug use in patients with cancer. Expert Opin Drug Saf 2013. 

20. Akiyama J, Roorda AK, Triadafilopoulos. Managing Barrett’s esophagus with radiofrequency ablation. Gastroenterology Report 2013.  

21. Kommareddy S, Roorda AK, Legha P, Lombard C, Triadafilopoulos G. An elusive cause of severe gastrointestinal bleeding. Dig Dis Sci 2013.

22. Tandon A, Roorda AK, Legha P, Sangoi A, Triadafilopoulos G. Mellow yellow: diagnosis and management of of multifactorial postoperative jaundice. Dig Dis Sci 2016;61(8)2226-2230.

23. Ramrakhiani, H, Roorda, AK, Tran, T, Shetler K, Triadafilopoulos, G. Great Weight, Low Pressure–One Problem: GLP-1 Receptor Agonist-Associated Colonic Ischemia. Dig Dis Sci (2025).

ABSTRACTS AND PRESENTATIONS:

1. Rider JA, Roorda AK, Rider DL. An analysis of standards for antacid simethicone defoaming properties. Gastroenterology 1995;108:A32. 

2. Rider JA, Roorda AK, Rider DL. A critique of existing methods in the analysis of antacid simethicone defoaming properties. Gastroenterology 1997;112:A397. 

3. Rider DL, Rider JA, Roorda AK. One hundred consecutive percutaneous endoscopic gastrostomies (PEGs) in an elderly (average age 85) high-risk population with zero mortality and no intraoperative complications: a standardized team approach. Gastrointest Endosc 2000;51:Ab292. 

4. Gill KRS, Roorda AK, Allen M, Lee  J, Yamaguchi T, Binmoeller KF. Evaluation of wireless capsule endoscopy interobserver agreement among four different levels of expertise. Am J Gastroenterol 2005;100:S354. (Poster Presentation at the American College of Gastroenterology's 70th Annual Meeting, Honolulu Convention Center, Honolulu, Hawaii, October, 2005 and poster presentation at the American College of Physicians 2005 Northern California Chapter Scientific Meeting, Portola Plaza Hotel, Monterey, CA, October, 2005). 

5. Roorda AK, Gill KRS, Mendelson T, Peterson DL, Allen M, Binmoeller KF. Wireless capsule endoscopy in patients with leaky gut syndrome. Gastrointest Endosc 2006 April;63(5):AB172.(Poster presentation at the American Gastroenterological Association Annual Meeting, Los Angeles Convention Center, Los Angeles, California, May, 2006 and poster presentation at the American College of Physicians 2005 Northern California Chapter Scientific Meeting, Portola Plaza Hotel, Monterey, California, October, 2005).

6. Yague AS, Roorda AK, Allen M, et al. Incidence and outcomes of capsule endoscopy retention: An international study. Am J Gastroenterol 2006;101:S530. (Poster presentation at the American College of Gastroenterology’s 71st Annual Meeting, The Venetian Resort and Casino, Las Vegas, Nevada, October, 2006). 

7. Roorda AK, Tsoi E, Man K, Mulholland S, Yu H, Mendelson T. An unexpected cause of refractory upper gastrointestinal hemorrhage in a patient with platelet dysfunction. (Poster Presentation at the American College of Physicians 2006 Northern California Chapter Scientific Meeting, Portola Plaza Hotel, Monterey, California, November, 2006). 

8. Roorda AK, Marcus SN, Triadafilopoulos G. Early Experience with radiofrequency energy ablation therapy for Barrett’s esophagus with and without dysplasia. (Poster Presentation at the Stanford University Network for Translational Research in Optical Imaging (NTROI) Retreat, Stanford University, Palo Alto, California, January, 2007). 

9. Boparai V, Roorda AK, Marcus SN, Triadafilopoulos G. Esophageal and gastric pH profiles in patients with refractory gastroesophageal reflux disease treated with twice daily proton pump inhibitors. Gastroenterology 2007 132:A283. (Poster presentation at the American Gastroenterological Association Annual Meeting, Washington Convention Center, Washington, District of Columbia, May, 2007). 

10. Roorda AK, Marcus SN, Triadafilopoulos G. Radiofrequency ablation for Barrett's esophagus with and without dysplasia: A community-based, single-center experience. Gastrointest Endosc 2007;65:Ab282. (Poster presentation at the American Gastroenterological Association Annual Meeting and Digestive Disease Week, Washington Convention Center, Washington, District of Columbia, May, 2007). 

11. Sanchez-Yague A, Allen M, Caunedo-Alvarez A, Roorda AK, Sison CM, Gill KRS, Pizzute C, Romero-Vazquez J, Binmoeller KF, Herrerias-Gutierrez JM. Capsule endoscope retention incidence and outcomes in a large international series. [Poster presentation at the 6th International Conference on Capsule Endoscopy(ICCE), Madrid, Spain, June, 2007]. 

12. Roorda AK, Marcus SN, Triadafilopoulos G. Value of a novel multi-factorial scoring system as a diagnostic aid in the prospective evaluation of patients with reflux-like dyspepsia. Am J Gastroenterol 2007;102:S151. (Poster presentation at the American College of Gastroenterology’s 72nd Annual Meeting, The Pennsylvania Convention Center, Philadelphia, Pennsylvania, October 2007 and poster presentation at the American College of Physicians Northern California Chapter Scientific Meeting, Portola Plaza Hotel, Monterey, California, December, 2007). 

13. Roorda AK, Marcus SN, Triadafilopoulos G. Algorithmic approach of patients presenting with heartburn and epigastric pain refractory to empiric proton pump inhibitor therapy. J Clin Gastroenterol 2008;42:S16. [Oral and poster presentation at the World Organization for Specialized Studies on Diseases of the Esophagus (OESO) 9th World Congress, Monaco, Monte Carlo, April, 2008]. 

14. Roorda AK, Marcus S, Triadafilopoulos G. Validation of a novel scoring system as a diagnostic aid in patients with reflux-like dyspepsia. Am J Gastroenterol 2008;103:S30. (Poster presentation at the American College of Gastroenterology’s 73rd Annual Meeting, Gaylord Palms Resort & Convention Center, Orlando, Florida, October, 2008). 

15. Roorda AK, Ostrinsky Y, Kupec JT, Goebel SU, Shamma'a JM, Sundaram U. Endoscopic approaches to retained capsule endoscopy. Am J Gastroenterol 2009;104:S386. (Poster presentation at the American College of Gastroenterology’ 74th Annual Meeting, San Diego Convention Center, San Diego, California, October, 2009). 

16. Roorda AK, Miranda M, Ju J, Sundaram U. Utility of SpyGlass in preventing common bile duct trauma during ERCP with “clip stone” extraction. Am J Gastroenterol 2010;105:S216. (Poster Presentation at the American College of Gastroenterology’s 75th Annual Meeting, Henry B. Gonzalez Convention Center, San Antonio, Texas, October, 2010). 

17. Kupec JT, Roorda AK, Sundaram U. Routine fluid aspiration during direct visualization cholangioscopy (SpyGlass) ncreases Diagnostic Yield. Am J Gastroenterol 2010;105:S68. 

18. Roorda AK, Manoharan P, Kekuda R, Coon S, Sundaram U. Peroxynitrite uniquely regulates brush border membrane anion/HCO3 -  exchange in rat small intestinal epithelial cells. 2011 E.J. Poster Presentation at the Van Liere Memorial Convocation Memorial  Convocation and Health Sciences Center Research Day Event. March 11, 2011. West Virginia University. Morgantown, West Virginia. 

19. Roorda AK, Manoharan P, Kekuda R, Coon S, Sundaram U. Peroxynitrite uniquely regulates brush border membrane anion/HCO3 -  exchange in rat small intestinal epithelial cells. Gastroenterology 2011;140:S662. (Poster presentation at the American Gastroenterological Association Annual Meeting, McCormick Place, Chicago, Illinois, May, 2011).

20. Weed MT, Manoharan PK, Roorda AK, Balasubramanian P, Sundaram U. NHE3 and butyrate: HCO3-  exchange are uniquely altered in the proximal colon in a rat model of colitis associated cancer. Gastroenterology 2012;142:S693. (Poster presentation at the American Gastroenterological Association Annual Meeting, San Diego Convention Center, San Diego, California, May, 2012). 

INVITED LECTURES AND GRAND ROUNDS:

September 30, 2011 “Update on Barrett’s esophagus” Department of Internal Medicine. West Virginia University School of Medicine, Morgantown, West Virginia. 

September 1, 2012 "How to manage symptoms after anti-reflux surgery (ARS)”  Post Graduate Course. World Organization for Specialized Studies on Diseases of the Esophagus (OESO) 11th World Congress, Lake Como, Italy. 

September 3, 2012 “Role of anti-reflux surgery (ARS) in Barrett’s esophagus” Plenary Session 7. World Organization for Specialized Studies on Diseases of the Esophagus (OESO) 11th World Congress, Lake Como, Italy.

2011 - Recognized by West Virginia University Hospitals as one of the top (99th percentile) providers in patient satisfaction surveys.

2010 - Selected as Chief Gastroenterology Fellow for 2010-2011 academic year

2008 - One of 12 posters selected by the congress jury for oral preesentation at the World Organization for Specialized Studies on Diseases of the Esophagus (OESO) 9th World Congress, Monaco, Monte-Carlo

2007 - First Runner Up, Poster Presentation, Research Category, American College of Physicians, Northern California Meeting, Monterey, CA

2001 - Letter of recognition for Clinical Pathologic Conference (CPC) analysis (top ten among medical school class)

1994 - Award for Exceptional Student Leadership and Service to University of California, San Diego, Revelle College