Our Staff

Liz Cruz, M.D. Gastroenterology


Dr. Cruz graduated from college in 1988 with a B.S. in Medical Technology. Prior to Medical School, she taught English for one year in Bangkok Thailand. In 1989, Dr. Cruz began her formal career in medicine by attending Loma Linda University School of Medicine in California. During medical school, Dr. Cruz was part of a student/staff physician team, which provided relief work to the natives along the Amazon River. She graduated from medical school in 1993 and then went on to do her Internal Medicine Internship under the auspices of the U.S. Navy at the Naval Hospital, Oakland, California.

Upon the closure of the Naval Hospital in Oakland, Dr. Cruz transferred and completed her internal medicine residency at the University of California, San Francisco. In 1996, she was deployed to Guam to fulfill her commitment to the U.S. Navy. While in Guam, she served as a Staff Internist at the U.S. Naval Hospital. During her active duty years in the Navy, she received the Meritorious Unit Commendation Medal as well as the Humanitarian Service Medal and the National Defense Medal for service during Operation Desert Storm. During her last two years in Guam, she was the Head of the Internal Medicine Division at the U.S. Naval Hospital.

In 2000, she went back to the University of California, San Francisco where she completed her training in Gastroenterology (GI). In 2004, Dr. Cruz moved to Arizona to join the Arizona Medical Clinic in Peoria. For two and a half years she served as a full-time gastroenterologist in both the outpatient and inpatient settings doing the full range of general gastroenterology including endoscopic procedures as well as hepatology. In January 2007, Dr. Cruz joined Estrella Gastroenterology in Goodyear, Arizona. In January 2008, she opened the doors to her own practice, Dr. Liz Cruz Partners in Digestive Health.

Dr. Cruz was born in Los Angeles, California, and was raised in Orlando, Florida. She speaks fluent Spanish and enjoys her family, traveling, jazz music, and photography.

Dr. Cruz is a Diplomate of the American Board of Internal Medicine and the American Board of Gastroenterology. She is a member of the American Gastroenterological Association and the American Society for Gastrointestinal Endoscopy.


Neil Shernoff, M.D. Gastroenterology


As one peruses Neil Shernoff, MD’s curriculum vitae, many awards, leadership positions, innovations and publications that may be seen, they all validify a fine career.   However, there are two specific items that remind Dr. Shernoff as to why he wanted to be a doctor, he wanted to teach and to make a difference.

Dr. Shernoff grew up in an era of malignant professors and vowed, as a medical student, that if he would ever be in a teaching position, he would make learning fun. Having devoted a portion of his entire career to teaching and having been Teacher of the Year thrice, he believes he has fulfilled that vow.

In addition, Dr. Shernoff was a founding father of Arizona's first Liver Transplant Program. This was useful later when he had a case where the Arizona medical system denied a liver transplant to a young married mother with terminal auto immune liver disease.  Dr. Shernoff went on to fight for her, something three prior gastroenterologists were unwilling to do. As a result, not only did she receive her transplant but for the next two years, Dr. Shernoff teamed up with lawyers to overturn the state statute prohibiting liver transplants in adult Medicaid patients. Furthermore, Dr. Shernoff became a founding father of the Arizona Chapter of the American Liver Foundation, now a four state Desert Southwest Chapter.


Maureen Tyner, DNP-BC


Maureen has been a nurse for over 10 years and has been a Board Certified Nurse Practitioner since 2012. Maureen graduated with her Doctorate of Nursing Practice from Arizona State University in May 2017. She has an extensive background in women’s health, gastrointestinal medicine, trauma, and traumatic brain injury. Her focus is on individual holistic care. Born and raised in Pittsburgh, Pennsylvania she is a Steelers football fan and likes Pina Coladas and getting caught in the rain. She is not into yoga but is into champagne.


Raquel Rivas, FNP-C


Raquel graduated with her Nursing degree in 2013 from Chamberlain College of Nursing. She has been a Board-Certified Nurse Practitioner since 2017, earning her degree from Grand Canyon University. She has worked in family practice, regenerative medicine, allergy and wellness, geriatrics and gynecology / obstetrics. She was born in California, her mother, who is her biggest hero, is from Nicaragua and her father from Mexico - yes she is fluent in Spanish. She is married with two children and loves hanging at the park, playing basketball, going to the movies and baking. She has a strong faith in God and is excited to be a part of the Dr. Liz Cruz team!


Tina Nunziato, CHNC


Tina Nunziato graduated from the Arizona State University College of Business Honors Program in 1996 with a Bachelor of Science in Marketing. After graduation, Ms. Nunziato took a job as a Marketing Analyst for a local telecommunications vendor, now Lucent Technologies. She quickly moved out of market research and into business development as a Marketing Specialist where she worked on various new product and joint venture initiatives.

In late 1999, during the dot-com boom, Ms. Nunziato moved to San Francisco to start a web-based software company. Focused on the park and recreation market, the company went through many strategy iterations before it found its niche. In her role as COO and eventually CEO, Ms. Nunziato experienced all facets of the business from raising capital and product design to selling, training, and supporting customers.

In May of 2003, subsequent to selling her company to one of the industry competitors, Ms. Nunziato came back to her roots here in the valley. She accepted a position as the Director of Marketing with Carefx Corporation a healthcare software company in Scottsdale.

In 2007 Ms. Nunziato decided to try her hand in medicine when she started Dr. Liz Cruz Partners in Digestive Health with her life and business partner Dr. Liz Cruz. Ms. Nunziato and Dr. Cruz decided to take medicine one step further by offering a wellness program through their office. In conjunction with and to support this business Ms. Nunziato went back to school to receive her Certificate in Holistic Nutrition in 2010. Since then both businesses have been growing as they continue to help patients year after year with their digestive diseases, sluggishness, and weight gain.

It is the passion of both Ms. Nunziato and Dr. Cruz to get the digestive wellness message to as many people as possible as fast as possible so to help heal a nation.


Zsazsa Zuniga, Certified Nutritionist & Health Coach

Zsazsa Zúñiga was born and raised in Reynosa (Mexico), she graduated from college in 2009 from UANL in Monterrey Nuevo León, with an B.S. in Nutrition. She worked for 5 years in the Diabetes area in a Vascular Medical Clinic. In 2013, Zsazsa got married and moved to West Texas. She started her wellness education there by becoming a Nutritionist Health Coach (IIN) and since then, she has gotten very passionate about gut health because everything starts in the gut. In 2016, she moved to Brownsville Texas and soon became a mother to two amazing children, a boy and a girl. As a Mom, she is now more than ever interested in the importance of wellness and nutrition. She went back to school and in 2021 she got her Functional Gut Health Certification. Zsazsa enjoys big family gatherings, and loves spending quality time with her family. It nurtures her to connect with her love ones, including friends. Zsazsa is very excited to be part of the Dr. Liz Cruz team, even from Texas she feels like she is part of it all.

Patricia Cano, Certified Nutritionist & Health Coach


Patricia Cano joined Dr. Cruz's team as a Holistic Nutritionist in 2022.  She attended school to become a Holistic Nutrition and Wellness Practitioner in 2019 and then in 2020 was trained by the National Academy of Sports Medicine as a Fitness Educator and Behavior Change Specialist.  Her passion for helping others get well has led her to work in many different settings where she has supported individuals with various health conditions.  She believes that the best way to achieve happiness and health is to take a holistic approach.  Patricia who is fluent in Spanish, was born in Guanajuato, Mexico and was raised in Phoenix, AZ since the age of 2.  She enjoys spending quality time with her husband, daughter and son and loves the outdoors, reading, as well as expanding her knowledge in health and biblical studies.   


Anil Prasad, M.D. Pathology


Dr. Prasad is originally from India where he received his Bachelor of Medicine and Surgery and his M.D. in Pathology. He completed his Residency in Anatomic/Clinical Pathology and his Fellowship in Cytopathology at Henry Ford Hospital in Detroit, Michigan. Dr. Prasad completed his Fellowship in Surgical Pathology from Mayo Clinic in Rochester, Minnesota. Moving to Arizona in 2001, Dr. Prasad has been a Consultant for Arizona Cancer Center; an Assistant and Associate Professor for the University of Arizona; has been the Staff Pathologist, Co-Program Director of Molecular Pathology and Laboratory Services, Clinical Director of Surgical Pathology and Cytology and Pathology Research and Development at the Southern Arizona VA Health Care System; has been the Staff Pathologist and Vice-Chair of Pathology for the Department of Pathology at St. Mary's Hospital; and is now the Staff Pathologist for Dr. Liz Cruz Partners in Digestive Health, Northwest Medical Center, and Oro Valley Hospital.

Highly accomplished, Dr. Prasad has won many honors and awards; written more than 65 abstracts and papers, book reviews, and book chapters. He is a sought after National Presenter and Lecturer and Grant Recipient. Dr. Prasad is Board Certified in Anatomic and Clinical Pathology and Cytopathology, he holds many Professional Affiliations, and serves on the Surgical Pathology Quality Assurance Committee.

Outside of his professional obligations Dr. Prasad enjoys spending his free time with his family.


Katrina Olivas – Medical Assistant


Katrina Olivas was born and raised in Phoenix Arizona. She attended the International Institute of America’s in 2008 to get her Medical Assistant degree. Katrina has been with Dr. Liz Cruz Partners since 2012 after working two years in an OB/GYN office and a year with a vascular/cosmetic surgeon. She has two beautiful daughters whom she adores. Katrina loves doing arts and crafts, scrap booking, watching movies and the news, and being outdoors.


Ray Rodriguez – Scheduler / Referral Coordinator


Raymond (Ray) Rodriguez was born and raised in Tolleson, Arizona. Ray started his career in the medical field in 2009. He graduated from Trendsetters CNA Academy as a Certified Nursing Assistant and Medication Technician. He enjoys the company of his family and friends and his only wish is to one day explore Europe and the Hawaiian Islands. Ray enjoys participating in and celebrating his Mexican Catholic traditions. Ray has always believed that the impossible is possible and his only hero is God.


Denise Mata – Procedure Scheduler


Denise Mata was born and raised in Phoenix, Arizona. She finished school to be a Medical Assistant in 2012 and has been in the medical field ever since. She loves to spend time with her three daughters and fiancé. Their favorite place to go is Dutch Bros. – her favorite is the Double RainBro black tea, it’s her go-to drink! She really enjoys Sundays with her family, going to church, and then having lunch. Her favorite restaurant is Oregano’s Pizza Bistro, she loves the Pablo Picasso salad. She also enjoys volunteering at her daughter's school and watching her play soccer.


Kristina Menchaca – Medical Assistant

Kristina Menchaca was born and raised in Los Angeles, CA. She moved to Phoenix in 2013 soon after receiving her Associates in Science as a Medical Assistant from Everest College. She's worked as a Medical Assistant at a laser vascular surgery center in addition to Southwest Kidney Institute, before joining Dr. Liz Cruz's team in 2022. She loves spending time with her family, including her dogs. She enjoys exercising, hiking, traveling, swimming, and watching movies. She feels blessed to be working with Dr. Cruz and considers her work team part of her family.


Josseline Villarreal - Receptionist

Josseline Villarreal was born and raised in Phoenix, AZ. She attended North High School and graduated in 2019. Josseline has worked many customer service jobs before joining Dr. Liz Cruz's team as a Receptionist. She worked as a receptionist for both a pet clinic and Clinica La Familia. Josseline has also worked in a bakery and as a caregiver. She loves Arizona sunsets, but her favorite time of the year is when she visits her Grandma in Torreon, Mexico.    


Maria Salcedo – Clinical Research Coordinator and Back Office Support

Born in Tijuana, Mexico and raised in California with her 2 sisters, Maria Salcedo started her career in the medical field graduating as a Medical Assistant in 1996. She has worked many customer service and back office support jobs throughout the years. Maria enjoys meeting new people every day and helping however she can. She enjoyed her time spent as a stay-at-home housewife and mother of three. Maria is new to Phoenix and is enjoying every day getting to know everything that Arizona has to offer. She also enjoys swimming and going out with friends and family. Maria takes advantage of what life has to offer and is currently enjoying every minute here at the Dr. Liz Cruz office.  


Karen Nunziato – Back Office Support

Karen was born in Chicago, Illinois and moved to Arizona in 1984. She raised three children, which was her joy in life. She started working at the practice as the receptionist when Dr. Cruz first opened her doors in 2007. Although she retired in 2012, she couldn’t stay away and she came back in 2021 as back-office support. She's enjoying her work and loving her flexible schedule. She loves to cook and bake; she makes many people happy with sharing her wonderful treats.


Elizabeth Cruz Sr. – Forever Back Office Support


It is with a sad heart that I announce the death of my Mother, Elizabeth Cruz.  She passed away from COVID in August of 2021.  She had worked for the practice since it's inception in 2007 and I know many of you have interacted with her over the years.  She has been and will continue to be missed very much.  I really appreciate the outpouring of love I've received from so many patients.  Although she can never be replaced, we've asked our billers to step up their efforts with us and be in charge of procedure authorizations, deductible and benefit calls.  I love you Mami - you will forever be my back-office support!  Rest in peace...until we meet again!


"Dr. Cruz and Tina are the most caring and knowledgeable people I ever met." - Marse M.

Dr. Liz Cruz is Partners to your health for you
and your loved ones

After years of offering her digestive wellness knowledge, products and services to her patients and seeing amazing results time and again, Dr. Liz Cruz didn't want to stop there. "This information and these tools need to be shared with everyone now more than ever! It's never too late to change how you feel."– Liz Cruz M.D.

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