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Q: How soon should I cancel my procedure if I can’t make it?

A: If you absolutely must cancel your procedure, please do so at least 7 days in advance so that we have time to notify surgical center.  This will help them to cancel your case in time and avoid a possible bill.


Q: Should I take my medications the morning of the test?

A: Yes. You should take all of your usual medications, not supplements (including blood pressure medicines) with a sip of water several hours before your procedure. EXCEPT DIABETES MEDICATIONS SHOULD NOT be taken the morning of the procedure since you have not eaten. Additionally, Check with your doctor regarding holding ANY BLOOD THINNERS (such as COUMADIN, PLAVIX, AGGRENOX, etc) or ASPIRIN CONTAINING MEDICINES 5-7 DAYS PRIOR TO THE PROCEDURE. If you have further questions, please call the office


Q: Why do I need to be on a clear liquid diet the entire day prior to my colonoscopy?

A: Your colon needs to be clear of stool the day of your test. If you eat solid food the day prior to your test, your bowel is still processing the food and creating stool. If you have stool in your colon during the procedure, this impairs the doctor’s view, resulting in a possible repeat of the prep and the test.


Q: How do I know I have a good prep after I finish my Prep solution?

A: Once you finish drinking your prep, the stool looks like urine, which is a clear yellow color without any particles. That’s the result you aim to achieve.


Q: Should I finish my prep even if my stool appears clear?

A: Yes. Sometimes there is stool in the upper parts of the colon that comes out with the last several sips of the prep, so you should always finish the prep as instructed.


Q: What if I encounter nausea and vomiting?

A: If you have a sensitive stomach and encounter nausea and vomiting, then pick up nausea medications to take during or before you start the prep process.


Q: I lost my instructions for preparation, what do I do?

A:  Please click here to view a copy of prep instructions (please pick the right instruction that matches your Rx). Please call the office if you have further questions.


Q: Can I still have my procedure if I am on my period?

A: Yes. For your comfort, we do suggest that you wear a tampon.


Q: Why can’t I drive myself home after my procedure?

A: Due to the type of sedation we use, your judgement and reflexes are impaired. Therefore, it is unsafe for you to operate a vehicle or machinery until the day after your procedure.


Q: Can I work the day after my procedure?

A: You will be back to normal the day after, so you can return to your usual schedule.

Q: What happens after my procedure?

A: Dr. Zheng's staff will call you to check in with you regarding your procedure experience.  If a biopsy was taken or a polyp was removed, they will also schedule a (virtual) follow up appointment so that Dr. Zheng can discuss result with you.  The follow up appointment typically is 1-2 weeks after your procedure.  If you prefer skipping follow up appointment, your result will be emailed to you, with recommendations.  All procedure and pathology results are forwarded to your primary care physician and/or referral physicians as well.

Q: What about reminds for future procedures?

A: Dr. Zheng office will send email remind to you a month before you are due for (repeat) procedure to give you time to make arrangement.

Q: Where do I get my lab works done?

A: You can get lab works at labCorp, Quest,  John Muir, or Bass

Q: Where do I get my radiology study (X ray, ultrasound, CT, MRI, etc) done?

A: You can get radiology study at NorCal image or John Muir image center

Q: What if I have questions regarding my medical charge or bill?

A: Dr Zheng’s office uses a separate medical billing service.  The best way to get billing related questions answered is to contact them directly @ Zen Medical Services phone (408) 673-0936 email:

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Patient Forms

Office Documents

Patient Forms

Speed up the pre-appointment process by filling out the following forms online at patient portal. New patients is advised to provide these forms before their first appointment:

If you need additional help on completing documents online, please call us at 925 384 9276, our staff can help, or you can simply arrive 15 minutes earlier and our staff will assist you!

We are making things super easy for you and you can spend more time on things you here

You can also login into your patient portal to view detailed pre-procedure instructions. 

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Questions? Please Contact Dr. Zheng for a Consultation

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