CLOSED TO PATIENTS WHO HAVE NOT BEEN SEEN SINCE NOVEMBER, 2017

Please contact your primary care physician for prescriptions and other assistance

Dr. McMahon is a Board Certified Gastroenterology specialist and is a Fellow of the American College of Gastroenterology (FACG).


He is a Graduate of Washington University Medical School in St Louis


He performs screening and diagnostic colonoscopies, polyp removal, upper endoscopy and digestive health consultations.

Meet the Doctor

  • Gastroenterology
  • Digestive Health
  • Colonoscopy
  • Endoscopy
  • Polyps
  • Ulcers
  • Colon cancer screening​

Colonoscopy Doctor

CLOSED TO New Patients

Office Hours

By appointment only

Closed to New Patients

Closed to patients who have not been seen since November 2017

Contact Us

Robert McMahon MD 

Gastroenterology Specialist  (Colonoscopy Doctor)

Colonoscopy Screening

in St Louis, Missouri.

Robert McMahon MD

1610 Des Peres Rd Ste 150 

St Louis MO 63131 

(314) 492-4100

Call Us:  1 (314) 492-4100

Additional Information:


The American College of Gastroenterology has resources (patients.gi.org) including "What is a gastroenterologist"


Some Gastroenterologists receive special recognition from national societies when they demonstrate extraordinary achievement in research, teaching, or other unique service to the field of Gastroenterology. The American College of Gastroenterology designates such physicians as "Fellows" with the suffix FACG added to denote these honors. This means that these physicians have fulfilled the respective organizations’ rigorous requirements to gain this added distinction.