Board Certified Gastroenterologist (Colonoscopy Doctor)

Colonoscopy Screening

in St Louis, Missouri.

Please examine​ website and see multiple verified actual patient positive reviews posted under Dr. McMahon's profile.  

Meet the Doctor

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

Colonoscopy Doctor

We accept most public and private insurance plans. We may also offer special pricing for cash-paying patients for most procedures.

Health Insurance

New Patients

Practice is closed to new patients at this time.  Prior and existing patients only, procedures only.

Robert McMahon MD in St Louis; Colonoscopy Doctor. Endoscopy Doctor.

Call (314) 492-4100 for procedure scheduling.

Contact Request

Robert McMahon MD

1610 Des Peres Rd Ste 150 

St Louis MO 63131 

(314) 492-4100

Contact Us

Call Us:  1 (314) 492-4100

Office Hours

By appointment only

Closed to New Patients


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.

Robert McMahon MD 

Additional Information:

The American College of Gastroenterology has resources ( 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.