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Welcome to

GRANITE STATE
GASTROENTEROLOGY

Our experienced team delivers high-quality,
friendly service with an emphasis on patient
choice and communication.
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Welcome!

Granite State Gastroenterology

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 five physicians Board Certified in Gastroenterology and four Advanced Practice Practitioners (APPs). Three of our APPs are Physician Assistants, and one is a Nurse Practitioner.

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Provider Spotlight

GS-Gastro-headshot-Tsistrakis

Steven Tsistrakis, M.D.

Dr. Tsistrakis received his medical degree from Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, PA. He finished his residency at the Icahn School of Medicine at Mount Sinai Beth Israel in New York City. He completed his fellowship in Gastroenterology and Hepatology at New York Presbyterian in Queens, NY where he served as Chief Fellow.

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Latest News

Granite State Gastroenterology News

Our Services

Granite State Gastrointestinal will handle all your gastroenterology needs, from gastroesophageal reflux treatments to colonoscopies.
home-colonoscopy

Colonoscopy

We screen for colon cancer, remove polyps, and treat rectal bleeding.
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Upper Endoscopy

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

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Capsule Endoscopy

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

home-peg-placement

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.

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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.

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Expertise

We have expertise in liver disease,  hepatitis C, inflammatory bowel disease, irritable bowel syndrome, disorders of the pancreas, and anal and rectal disease.

Great Service

We pride ourselves on treating each patient with tailored, individual care. We have multiple channels of fast communication with our
patients.

Reliable Care
Our patients can rely on us to get them the care they need and to explain everything we are doing to help them. Transparency and understanding are key.
Multiple Locations
We have multiple convenient locations for procedures, labs, and imaging studies, allowing patients to choose the right facility for them based on location and insurance coverage.
Your Comfort

Our patient’s comfort is always
at the top of our minds. We
offer pain-free endoscopies
and use the best equipment
available for all services for
maximum comfort.

Team of Experts

Our team provides expertise
in general gastrointestinal
disorders, inflammatory bowel
disease, esophageal motility
disorders, liver disease, and
treating Hepatitis C.

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.”


The staff was very friendly, kind, and professional. Dr Chowdhury was thorough, very informative, and helpful.
Dr Chowdhury was very patient she took her time reviewing my medical history and was very helpful in answering questions for me. I would definitely recommend her to someone seeking a good gastroenterologist.
Looking for good GI Dr? Go to Granite State. Ty, Allison, and Megan -- the best team.
What a great place! Dr Horton is simply the best! So personable, just great!!!
The best experience I have ever had with a doctor. The staff is welcoming, the office is clean, and I felt very at ease.
I saw Dr. Laura Horton at Granite State GI and she was fantastic. She was very knowledgeable, had great suggestions, and was very easy to talk to. I highly recommend her.
Dr. Horton is an excellent and thorough doctor! She listens to your questions. She answers any and all questions or concerns you may have and provides explanations and advice should you seek those too. I am very happy to have her as my gastroenterologist!
Everyone that worked there was so friendly and helpful. I'll be back. The doctor was wonderful in every way. I'm so happy to have seen her and hope to continue with Granite State.
This practice has great future!

Leave us a Review

Leave us a Review
Our entire staff is dedicated to providing high-quality medical care, emphasizing patient choice, and constantly improving our patient communication. We treat each patient with individual, detailed care tailored to their specific needs. Each patient’s experience is valuable to us, and we strive for everyone to leave with all questions answered! To constantly improve our patient communication, we have expanded our staff and communication options to ensure everyone is satisfied with each interaction, whether scheduling, asking a question, or coming in for an appointment.