The experience you can trust for the important tests you need.

We understand that visiting the gastroenterologist may be a new experience for you and that you may be in pain or worried about your health. That’s why all the staff at Advanced Gastroenterology focus on making you feel comfortable and confident in our care. Dr. Samuel K. Sim, Dr. Frank Yeh, and our medical team take extra care to listen to your concerns, answer all your questions and thoroughly explain your condition and treatment options.


The doctor uses a lighted tube to look inside all or your colon. The doctor will be looking for a growth that could be cancer or a polyp that could turn into cancer. If he sees something that concerns him, he can take a piece of the growth and test it for cancer. Read more..

Please click on this link for Procedure Preparation Instructions

Upper Endoscopy/Esophagogastroduodenoscopy (EGD)

Upper GI endoscopy, sometimes called EGD (esophagogastroduodenoscopy), is a visual examination of the upper intestinal tract using a lighted, flexible fiber optic or video endoscope, which is usually performed on an outpatient basis. Read more..

Please click on this link for EGD Preparation) Procedure Preparation Instructions

Flexible Sigmoidoscopy

Flexible Sigmoidoscopy lets your doctor examine the lining of the rectum and a portion of the colon (large intestine). Read more..

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