I'm not a patient yet. But because it is currently open enrollment, so confused about finding the right insurance to see Dr. Nguyen and Dr. Chen for 2020. Sammie Huynh from the office have been so helpful with answering my questions promptly. It is rare to meet someone willing to take time away from their busy day to answer insurance questions from someone that is only a potential patient. thank you so much Sammie. read more

Dr Nguyen is very smart and patient and gives good advice and treatment His staff also great even state ekc terrine to help me read more

I've truly never had such a horrible experience with a doctor before in my life. The office staff was incompetent - unable to answer direct questions, return calls in a timely matter, were rushing in office and so anxious. I started seeing the Dr in August of 2024 and was in extreme pain - I had asked then for a SIBO test. I pushed and pushed but after months of other testing (blood work, ultrasound, stool tests, colonoscopy, endoscopy) I was finally given a SIBO test. The company they did it with sent the doctor the entirely wrong test results and I had to be the one to call the company and get the correct test results which diagnosed me with SIBO. This happened in June of 2025. The doctor tried to tell me this was psychological. Overall, horrible care... I changed doctors finally and am receiving the care I finally need. Go elsewhere to someone who will listen and not go for a cash grab. Truly, the worst medical experience I've ever had. read more

Today I went for my first appointment with this doctor Ken. Although I arrived early like they asked which was at 2:45 PM, by 3:30 the NP entered the room and asked me questions about my case. After I talked about my health issues I'm thinking that Dr Ken was going to come to the room and exam my abdomen before deciding what tests would be necessary for my case, but guess what? The NP went ahead and escorted me back to the front desk in order to schedule a colonoscopy and endoscopy. I asked him if the doctor was going to meet me or talk to me and he said it was not necessary! Is it even legal? I had to co pay a visit to a doctor who didn't even bother seeing me? I don't care about the amount of credentials he possesses, it's out of the question, unacceptable to go through this humiliating situation for the price I pay for my health insurance!!!! On top of that, the parking lot doesn't accept credit or debit card! I had to re park the car and run to an ATM to get cash. What a ripoff! Don't waist your time! read more

I've been working with Dr Ken Nguyen for several years now and I have to say I am so pleased with the results. He is very knowledgeable, patient, and a true comfort with the level of professionalism in his area of expertise. I have been in remission with my U.C.Crohn's for quite some time under his supervision and my health is continuing on the up and up even years after my initial diagnosis. The only downside to this is he can be difficult to reach at times and you will have to wait a bit to schedule a visit, but that is to be expected when you are receiving care from one of the best in the business, and it is well worth the wait. Thank you Dr. Ken!!! Update; I really wish I had a positive follow up but I have to say the events of the last couple weeks have left me completely disappointed. I had requested clearance for an upcoming surgery to no avail, and after 6 months of attempting to obtain 1 clearance the surgeon has now dropped me due to the incompetence of Dr. Nguyen's office. I am now back to finding a surgeon who will work with me and I am still awaiting clearance for a surgery that is now officially cancelled. I will be looking for another G.I. specialist as well as another surgeon. Complete incompetence!!! read more

I've called them 3 times and I waited around 45 minutes with each call, which is understandable with Doctor's Offices. They let you know what place you are in the queue and I made it to #1 every time. The first time, the call just "dropped", but was not on my end for I was waiting in the same spot for 45 minutes. So I thought that was odd. Called a second time. Waited another 45 minutes, queued 5, 4, 3, 2, 1. When it was my turn, I heard them pick up the phone then hung it up. HUNG IT UP AFTER WAITING FOR 45 MINUTES!!! Tried a third time and the same thing happened. I get dropped as soon as it's my turn. I know they may be busy that's why I was very patient because I've worked at a Doctor's office as well, but to just hang up the phone 3 times, is unacceptable. I hope they understand that people wait for a long time to speak to them and they can't even be bothered to say, "Hello, can I put you on hold?" I ended up driving about an hour to the office to talk to them. This experience is one I'm sure a lot have gone through and hope they fix this problem. Just keep me in the loop and I'll be patient and wait. I value their time and I wish they valued mine. read more

This review is actually for Dr. Tim Chen, Dr Ken Nguyen's partner in the same office. My mom had a wonderful experience with Dr. Tim Chen. Though I don't want my mom to be sick again, Dr. Nguyen's office would definitely be my first choice if she ever becomes sick again. Dr. Chen speaks perfect Mandarin (native speaker fluency), and communicated with my mom very well. He made several calls after each appointment and medical exam to promptly notify me of the results, explain what they meant and discuss the next steps. Before the colonoscopy, he came to talk to my mother in Chinese and reassured my mother everything is going to be Ok. The whole process was smooth and painless. Since my mom doesn't have medical insurance, Dr. Chen made every effort to help us avoid unnecessary costs. He made sure to only give my mom high yield exams first before moving onto the next one. He even made an effort to call pharmacy to inquire about the price of the medication to make sure it is affordable to us. My mother felt she was truly taken care of. We can't thank Dr. Chen enough for his care and patience. read more

Dr. Ken Nguyen is probably one of the best doctors I have had the opportunity to meet. Though I was not his patient directly, he managed the care of my client. I work directly with individuals with developmental disabilities as a Registered Nurse and I was really happy to see the attentiveness and exceptional care that Dr. Nguyen provided at every meeting. He took the time to explore all avenues of care and was well informed and resourceful. Dr. Nguyen truly is a GREAT doctor and trusted patient advocate. I would confidently recommend him to my family and friends. read more

Dr. Ken Nguyen is an excellent doctor and I'm very glad to know him. He was recommended by a friend and actually he's not a good doctor, he is a GREAT doctor. He listens to you and is very understanding and last but not least, he makes you feel very comfortable so you can tell him about your issues and concerns and he responds kindly and professionally. I would give him 10 stars if I could! Great guy, awesome Doctor! read more

Truly horrible customer service. Doesn't respond to forms fill out on the site listed here. Called directly and they made me wait 30 minutes to say "I won't help you at all." Really a horrible experience read more

Horrible! Unprofessional and lacks any empathy. Went to see him because of side pains. He recommended a couple of tests to be run. I did the tests and he NEVER got back to me. I sent him THREE emails asking to be contacted. I called four times. FOUR TIMES. And only then did he contact me over the phone and didn't even offer any recommendations or any next steps. He actually asked me WHY I wanted him to call me back. I went and took exams and he's asking me why I wanted him to call me back. After almost one month. Horrible, unprofessional, uneducated and lacks any empathy. Do not go to him! read more

Here the doctor is very dedicated, the service staff and guides the patient enthusiastically and attentively

I just had a follow up treatment on telehealth with Dr Nguyen today. I was dying to find out if my gastritis test was positive or negative. Then he looked for the result and told me he didn't recieved it yet, it was kind of startled me because I was worried about it for months. Then he told me that the receptionists will call the lab and find out about the results and they will call me in 15 minutes. Then later one receptionist called and said the result was negative, I felt such a big relief and was so happy. But before that, Dr Nguyen gave me good treatment on telehealth, I could ask him any questions. He told me to eat more fruits and vegetables, it could help my h pylori. I felt, he and the whole team of receptionists and nurses are very cooperate with each other, I highly recommend you go there if you have gastritis or colon problems. Dr Nguyen is a little bit expensive on the follow up visit, he told me his medicine will killed 99% of the bacterias, and it did, he cured my gastritis, he and his team are worth every penny. Go to Insite Digestive Health, it's worth it. read more

Dr. Ken Nguyen is extremely knowledgeable and his staff is always friendly and helpful. Thanks to Dr. Ken Nguyen, my conditions have improved significantly. I will totally recommend Dr. Ken Nguyen to my friends and family. read more

Dr. Nguyen is really friendly and nice. He shares the office with doctor Tim Chen. They are located on the 4th floor of the SG medical plaza across from SGV medical center. Saw both of them at their office. They are the best GI duo you'll ever meet. read more

I usually don't review doctors that my parents go to but I wanted to leave a note specifically about Dr. Ken. He is the first doctor that made me feel comfortable leaving my parents to be cared for. He is a great listener which is very rare nowadays. I could tell there was a difference with his office visit. My parents actually had a conversation with him about their history and concerns. For anyone who wants a great doctor for their loved ones, dr Ken is someone that I confidently recommend. read more

I saw Dr. Nguyen for the first time when I was in pain due to a stomach ulcer. He listened to all of my concerns and prescribed me just what I needed to get through it. I would definitely recommend him for any of your GI needs! read more

I went to inSite Digestive for preventative testing and saw Dr. Ken Nguyen. From beginning to end, i.e. from scheduling the appointment, receiving instructions, completing paperwork and all the way through to my procedure with Dr. Nguyen, the entire experience was very organized and professional. The office staff is competent and efficient as well. For a repeat test, I really would not want to go anywhere else! read more

I met Dr. Nguyen and Dr. Chen about a month ago through the San Gabriel Chamber of Commerce. Made an appointment to understand what he does. I then scheduled a colonoscopy for a routine check since I'm 46 years old. I was real nervous, hoping everything would be okay. The staff made me feel comfortable, they answered all my questions and when the surgery was scheduled, it was a seamless experience. Thank God all is well. I appreciate the Dr Nguyen for being so supportive in making me feel comfortable no matter how nervous I was. Truly an amazing place. I give me 2 thumbs up. 5 stars and a 10 for customer service. I recommend anyone over 45 years old to make an appointment. Get a routine checkup. Be proactive not reactive! read more

This review is actually for Dr. Tim Chen. Came in today for some stomach issues. Dr. Chen was really informative and he takes his time to explain everything throughly to me. He didnt just give me a diagnose and sent me off, he gave explanation and options for me. Not only will I recommend him to my families and friends , I would recommend him to all Yelpers with any GI problems. read more

I took my mom to go see Dr. Ken Nguyen. Dr. Nguyen was recommended to me by a close friend. Both my mom and I really enjoyed our visit with Dr. Nguyen. He is a very caring and friendly doctor. He took his time to explain things in simple words that both my mom and I can understand. I would recommend for my friends and family to come see Dr. Nguyen. read more

Dr. Nguyen took care of me efficiently, answering all my questions.

Dr. Ken Nguyen is a great GI doctor and helped me immensely with my urgent health issues. He was very thorough and communicative in both English and Vietnamese. Both he and his staff were very friendly and help me navigate through confusing insurance issues. I had such a pleasant experience with him that I quickly made the switch to have him as my primary GI doctor. I would recommend him to anyone. read more

Dr. Ken is truly a one of a kind GI doctor! It's rare to find a doctor who is knowledgeable with good bedside manners these days. He answered my questions thoughtfully and made sure I understood everything. I'm so grateful to have found him. I would definitely recommend him to my family and friends. read more

Dr. Ken Nguyen is very professional, friendly, and informative. He took his time to explain and answered my questions and concerns. He is on time with the schedule appointment. The office has friendly staffs and they are multilingual. I am grateful to have received care from him. read more