[4:55 PM] Michelle Dennison-Bunch

See the experts about your gastrointestinal health.

Clearwater Gastroenterology is dedicated to providing affordable care that betters the entire community in Lewiston, Idaho and the surrounding area.

No referrals are required. Just call to make an appointment.

(208) 743-4373

Experience You Can Trust

Dr. Dettwiler has specialized in Gastroenterology since 1986.  He has a special interest in preventing colon cancer.  He encourages his patients to have adequate exercise and a healthy diet to reduce the risk of lifestyle related diseases. He is a member of the American Gastroenterology Association, Idaho Medical Association, American College of Gastroenterology, and MGMA.

Dr. Dettwiler at Clearwater Gastro

Measured quality, proven value


Colonoscopy enables your doctor to examine the lining of your colon (large intestine) for abnormalities.

pH Testing

Esophageal pH monitoring used for the diagnosis of gastroesophageal reflux disease (GERD).

Esophagogastroduodenoscopy (EGD)

EGD enables your doctor to examine the lining of your upper intestinal tract.

Breath Tests

The H. pylori breath test is a simple and safe test used to detect an active H. pylori infection.

Office Visits

Please contact us to schedule an appointment for personalized care for your gastrointestinal health.

We have an incredible staff

Here for YOU!

Community Involvement

Each year during March which is Colon Cancer Awareness Month, Clearwater Gastroenterology, Gem State Endoscopy and Pathologist’s Regional Laboratory team up to offer no-cost screening colonoscopies to those in need. We work with groups throughout the community to find those who meet the criteria and are without medical insurance. For more information about screening colonoscopies, please contact us!

Schedule an Appointment Today!

To make an appointment and for all general inquiries call 208-743-4373. If this is an emergency, please call 911 or go to the nearest Emergency Department.

Online Pre-Registration

We provide important medical communication via our Patient Portal. 

Colonoscopy Prep Instructions

We have several different instruction packets to help prepare for your procedure.

"In a town with very little options for Healthcare I feel super lucky to have landed in this office. The staff is EXCELLENT. They actually treat you like a real person. "

"...I have PTSD and severe anxiety. Sometimes appts can be very difficult for me to get through. This was not the case here. I left feeling like I was in good hands."

"The doctor was super cool about some embarrassing private things that had to be discussed. I wish I could see them for ALL of my medical needs."

"I can't say enough good things about the dr either. He listened to every word I said and took actual handwritten notes of the appt."