Covenant Health is an innovative, Catholic regional delivery network and a leader in values based, not-for-profit health and elder care. We sponsor hospitals, nursing homes, assisted living residences and other health and elder care organizations throughout New England.


St. Mary’s Regional Medical Center has two gastroenterologists, board certified anesthesiologists and registered nurses providing services for patients of the St. Mary’s Provider Network, Community Clinical Services and others who routinely refer to St. Mary’s for diagnostics and medical treatment.

To maximize patient's comfort, shorten recovery and discharge times, all sedation is administered by our Anesthesia Service.

Please watch this important video to help you prepare for your Colonoscopy.

Meet Our GI Physicians

John Lewandowski, MD

Michael Sivulich, MD


  • Colonoscopy (screenings and follow-ups)

  • Gastroscopy

  • Esophageal Dilatation

  • Other standard GI procedures

  • In-patient consultations

  • Telephone consultations for providers to discuss any outpatient management issues/questions

Our gastroenterologists do not hold office hours for routine patient visits.  Chronic patients (for example, those with Irritable Bowel Syndrome, Crohns, etc.) must be managed by their primary care provider, or should be referred to another GI practice.

Hours:Monday - Friday 7:30 am to 4:30 pm
Phone: 207-755-3636
Fax: 207-755-3652



St. Mary's Health System • 93 Campus Avenue • Lewiston, ME 04240