Our Dedicated Surgical Staff


ilianaIliana Clauson – Office Manager

“On behalf of the office staff of Dr. Chang, I would like to welcome you! I work behind the scenes to ensure each patient is taken care of adequately. Our goal is that each of our patients are satisfied with their care while visiting our office.

If you have any questions or concerns, please don’t hesitate to give our office a call! Thank you for your interest in our services.”

My e-mail is iclauson@absspecialists.com


Stacie KnightStacie Knight – Patient Coordinator

My name is Stacie Knight and I’m happy and excited to join the staff of ABSS. I come to the office with years of experience in the medical arena including a period of time in bariatrics. I am very centered in customer service and solutions. All this and more will be used to make sure prospective and current patients have the best patient experience possible. Our whole focus is making sure your journey to better health is one of the best things that ever happened to you. I look forward to meeting you and being of service to you and your loved ones. Come by and see me, and let’s make this journey successful!

My e-mail is sknight@absspecialists.com


Lori Jochen & Yadira Aguirre – Patient Liaisons

We are the gears behind the machine! From the time that you first request information, up until you go to surgery, we will be with you…we help prepare patients for surgery and their appointments. We want you to know that you are not alone and we’re here to help.  We gather information such as: insurance benefits, weight history, diet and exercise notes, etc…. we want to make the process as easy and smooth as possible.

Our e-mail addresses are ljochen@absspecialists.com and yaguirre@absspecialists


Joe Gracia – Medical Assistant

I am the last person you see when you’re done with your appointment and ready to go. I’ll be glad to help you schedule your next appointment with Dr. Chang as well as any labs or other diagnostic testing ordered by Dr. Chang or Lisa.  When you need vitamins I’m the one to check with. I enjoy watching our patients as they head home with a smile after great results from their visits.

My e-mail is jgracia@absspecialists.com


Erin Davis – Receptionist

I am responsible for greeting you with a smile as you walk into ABSS, making sure you feel comfortable in your visit with us. I am the first person you see as you check in and begin your journey to a happy and healthier life.

My e-mail is edavis@absspecialists.com


Yesenia Rangel – Billing Representative

My name is Yesenia and I’m excited to join such a wonderful organization.

I bring my years of experience in billing and general medical  office to the office and will help in keeping the office run smoothly.

My passion for helping patients achieve a better and healthier life is perfect for what ABSS is all about.  When you’re in the office

stop by and say hello and let me know what I can do to help.

You can also reach me at my e-mail: yrangel@absspecialists.com


Chris Jochen – Physician Liaison

I am excited and honored to be Dr. Chang’s Physician Liaison.  In this role I have the pleasure to visit the offices of many of our referring physicians.  While there I interact directly with the doctors, PA’s and NP’s, nursing and referral staff, and the rest of the support staff in the offices.  I deliver clear clinical information about how Dr. Chang and the staff of Advanced Bariatric and Surgical Specialists can help patients in their journey to better health. I also share educational materials and work to facilitate any and all issues that may arise for the offices and patients in this process. A huge part of my message is that Weight Loss Surgery is the best answer for their Clinically Severe Obese Patient’s health issues.

If you are a physician looking to make a referral, I will make sure you have all the information and communication you need.

If you are a prospective patient I want to applaud you for taking this important step in your journey.  I will do everything I can to make your journey to better health successful.

My e-mail is cjochen@absspecialists.com

Our office (and staff) have donated more than $70,000 per year
from 2014-2018 to worthwhile charitable organizations. We care about our community!