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GASTROENTEROLOGY CLINICS OF NORTH AMERICA September 1998 Editor: Heather Cullen

Volume 27, Number 3 ISSN 0889-8553

Production Editor: Julia M. Benson

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Gastroenterology Clinics of North America (ISSN 08894553) is published quarterly by the W.B. Saunders Company. Corporate and editorial offices: The Curtis Center, Independence Square West, Philadelphia, PA 191063399. Accounting and circulation offices: 6277 Sea Harbor Drive, Orlando, FL 328874300. Periodicals postage paid at Orlando, FL 32862, and additional mailing offices. Subscription prices are $125.00 per year (US individuals), $153.00 per year (US institutions), $136.00 per year (Canadian individuals), $184.00 per year (Canadian institutions), $161.00 per year (international individuals), and $184.00 per year (international institutions). Foreign air speed delivery is included in all Clinics subscription prices. All prices subject to change without notice. POSTMASTER Send address changes to Gastroenterology Clinics of North America, W.B. Saunders Company, Periodicals Fulfillment, Orlando, FL 328874800. Customer Service: 1-800-6542452 (US). From outside of the US, call 1-407-345-4000.

Gastroenterology Clinics ofNorth America is also published in Italian by I1 Pensiero Scientific0 Editore, Rome, Italy; in Portuguese by Interlivros Edicoes Ltda., Rua Commandante Coelho 1085, 21250 Cordovil, Rio de Janeiro, Brazil; and in Spanish by McGraw-Hill Interamericana Editores S.A., P.O. Box 5-237, 06500 Mexico D.F., Mexico.

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