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Peninsula Gastroenterology Medical Group, Gastroenterologists
Redwood City: 2900 Whipple Ave | Suite 245 |Redwood City, CA 94062 • Phone: 650-365-3700
Mountain View: 2495 Hospital Drive | Suite 600 | Mountain View, CA 94040 • Phone: 650-964-3636

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Lower Endoscopic Ultrasound with Fine Needle Aspiration

Patient Procedure Instructions

Purpose of Procedure

To examine tumor or polyp in greater detail by analyzing each of the 5 wall layers of rectum or colon by using a small ultrasound probe which is passed from the rectum to the area of interest. Standard colonoscopy can only visualize the first layer and miss what is hiding beneath. EUS also provides much higher resolution images than CT scans or MRI’s and better assessment of small lymph nodes outside of the intestines. Surrounding organs such as the prostate, seminal vesicles, vagina, uterus, bladder, and blood vessels can also be analyzed. Biopsies can be obtained for diagnosis.

Preparation for the Procedure

Purchase Over-the-counter

  • 1 - 10 oz bottle magnesium citrate (laxative)
  • 1 - Fleet enema

One Day Prior To Exam

  • Take 1/2 bottle (5oz) of citrate of magnesia (laxative) at approximately 3:00 p.m.
  • Eat only clear liquids for dinner.
  • After midnight, do not eat or drink anything except medications with a small sip of water.

On The Day Of Your Exam

  • Use the fleet enema (follow instructions on the box) first thing in the morning when you wake up (allow yourself time to get to your appointment).

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Atherton Endoscopy Center

While you are a patient at Atherton Endoscopy Center, our highly competent and professional staff will care for you. Everyone from the receptionist to the physician embraces our philosophy of patient-focused care. Above all, our staff is friendly and concerned for your comfort.