(212) 427-8761 Midtown, Manhattan Manhattan Gastroenterology 51 East 25th Street, Ste 407 New York, NY 10010 (212) 533-2400 Union Square, Manhattan Manhattan Gastroenterology 55 W 17th Street, Ste 102 New York, NY 10011 (212) 378-9983. Our site is the source of information about the gastroenterology related conditions and procedures..