GRANITE STATE
GASTROENTEROLOGY
friendly service with an emphasis on patient
choice and communication.
Welcome!

At Granite State Gastroenterology, we are proud to offer friendly, courteous, and knowledgeable care close to home for patients with gastrointestinal tract, liver, and pancreatic disorders. We have a team of experts in general gastrointestinal disorders, inflammatory bowel disease, esophageal motility disorders, liver disease, and treating Hepatitis C. Our team consists of four physicians Board Certified in Gastroenterology and three Advanced Practice Practitioners (APPs). Two of our APPs are Physician Assistants, and one is a Nurse Practitioner.
In the News
GRANITE STATE GASTROENTEROLOGY DOCTOR NAMED FELLOW OF THE AMERICAN GASTROENTEROLOGICAL ASSOCIATION Fellowship Honors Superior Professional Achievement in GI Field
Londonderry, NH (February 12, 2025) – Granite State Gastroenterology announced today that Leon P. McLean, MD, PhD, MPH has been named Fellow of the American Gastroenterological Association (AGA), the nation’s oldest, and most prestigious medical society dedicated to disorders of the gastrointestinal (GI) tract. Through the fellowship program, AGA honors superior professional achievement in clinical private or academic practice and in basic or clinical research. Fellowships are awarded to AGA members whose accomplishments and contributions demonstrate personal commitment to the field of gastroenterology.
“It’s an honor to be named a Fellow of the American Gastroenterological Association. I’m fortunate to be part of a group of outstanding physicians and advanced practice providers at Granite State Gastroenterology, all of whom are committed to delivering the highest quality GI care to our patients in southern New Hampshire and surrounding areas,” said Leon McLean, MD, PhD, MPH, AGAF.
“AGA Fellowship recognizes AGA members with exceptional professional achievement in the field of gastroenterology and hepatology. AGA is proud to announce the 2025 AGA Fellowship inductees who have been recognized by their peers and community as being at the forefront of our field. Congratulations to the entire group of inductees,” said Barbara Jung, MD, AGAF, AGA Institute President. Institution Boilerplate
Granite State Gastroenterology (GSG) is a private community GI practice based in Londonderry, NH with satellite offices in Bedford, Windham, Raymond, and Berlin. GSG gastroenterologists perform procedures at the Surgical Center of New Hampshire at Derry, the Bedford Ambulatory Surgical Center, Parkland Medical Center, Catholic Medical Center, and Androscoggin Valley Hospital.
About the AGA
The American Gastroenterological Association is the trusted voice of the GI community. Founded in 1897, the AGA has grown to include 16,000 members from around the globe who are involved in all aspects of the science, practice and advancement of gastroenterology. The AGA Institute administers the practice, research and educational programs of the organization. www.gastro.org.
Latest Updates
Granite State Gastroenterology Articles

The Role of Exercise and Movement in Digestive Health
When we think about the benefits of exercise, we often focus on weight loss, cardiovascular health, and mental well-being.

Understanding Irritable Bowel Syndrome (IBS)
Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder that affects millions of people worldwide.

How to Reduce Your Risk of Steatohepatitis (Fatty Liver Disease)
Steatohepatitis, commonly known as fatty liver disease, is a condition where excess fat accumulates in the liver, leading to inflammation and potentially severe liver damage.
Our Services

Colonoscopy

Upper Endoscopy
Using an upper endoscopy, we can evaluate and diagnose many issues and get you on the path to treatment or management.

Capsule Endoscopy
A capsule endoscopy can evaluate and image your small bowel by recording video as it travels through your system.

Gastrostomy Tube
(P.E.G.) Placement
At Granite State Gastroenterology, we offer the service of placing a gastrostomy tube, also known as a PEG tube, which provides supplemental feeding, hydration, or medication.

Bravo PH Probe Study
To evaluate symptoms of acid reflux, we can complete a test that will give us data on your symptoms, helping us diagnose and treat you.

Expertise
We have expertise in liver disease, hepatitis C, inflammatory bowel disease, irritable bowel syndrome, disorders of the pancreas, and anal and rectal disease.
Patient Stories
Trip to Health Worth Taking
When you find a good doctor, it makes the trip from Maryland to New Hampshire worth taking. That is exactly what George Sneed does. Sneed has extremely debilitating ulcerative colitis when it is active. His ulcerative colitis sometimes caused Sneed to go to the bathroom 10 to 15 times in four hours, making work or anything physical extremely difficult. Fortunately for Sneed, those times are now few and far between. He attributes much of his remission to the great care he has received from Dr. McLean.

Trust Keeps Him Coming Back
William Shakespeare once said, “Men of few words are the best men.” Granite State Gastroenterology patient John Moody, 75, of Derry, would certainly agree when it comes to Dr. Knut Roalsvig. “He’s a man of few words, but every word is important and means something,” said Moody. “Dr. Roalsvig asks a lot of questions, listens, takes copious notes, and is very thoughtful. You can almost see his brain working. He doesn’t let anything get by.”
