Please Note Mathers Rd. Medicare Clinic temporary entrance change Nov. 12-14 Learn More

Dr. Michael Ansstas Joins Multispecialty Care in O'Fallon

November 13, 2025 


// 

New Providers

HSHS Medical Group is pleased to welcome Dr. Michael Ansstas to HSHS Medical Group Multispecialty Care at 3 St. Elizabeth Blvd., Suite 5000 in O’Fallon. Dr. Ansstas is a board-certified gastroenterologist with advanced training in interventional gastroenterology. He specializes in diagnosing and treating a wide range of digestive conditions, including disorders of the gastrointestinal tract, liver and pancreas. Dr. Ansstas is known for his patient-centered approach, focusing on clear communication and individualized care.

He earned his medical degree from the University of Tishreen School of Medicine in Latakia, Syria. Dr. Ansstas completed his residency in internal medicine and fellowships in allergy and immunology at Saint Louis University Hospital in Saint Louis. He further specialized with a gastroenterology fellowship at Washington University-Barnes Jewish Hospital in Saint Louis and advanced interventional training at Cedars-Sinai Medical Center in Los Angeles, one of the nation’s leading programs.

Dr. Ansstas is board certified in internal medicine, allergy and immunology, gastroenterology and obesity medicine. He is dedicated to educating his patients, ensuring they understand their diagnosis and treatment options, and involving them in every step of their care.

To schedule an appointment with Dr. Ansstas, visit here or call 618-641-5803. New HSHS Medical Group patients may call the HSHS Medical Group Patient Advocate at 844-520-8897 to help set up their first appointment.
 
Dr. Michael Ansstas Joins Multispecialty Care in O'Fallon

Media Contact

Kelly Barbeau

System Director, Communications & Public Relations