About Us

Published date: March 9, 2012 | Modified date:

Dr. Stephen Wangen, co-founder and Medical Director of the IBS Treatment Center, and his staff have been successfully helping people resolve irritable bowel syndrome and chronic digestive problems since 1999. This success culminated in the 2005 opening of the IBS Treatment Center, the first clinic in the nation to focus solely on addressing this debilitating condition.

Over the years the IBS Treatment Center has cared for a wide variety of patients. Some patients have had IBS symptoms so severe that they spent a considerable amount of time in the hospital. Others are no less frustrated with the impact that it is having on their lives. The thread that tied them all together was that they had never seen an IBS expert, a doctor whose only mission is to help people solve IBS.  The IBS Treatment Center is proud to have cured thousands of IBS patients.

Although the clinics are located in Seattle, Washington and Los Angeles, California, patients come to us from around the country and the world, or they use our telemedicine service and avoid the travel. The map below gives you an idea about how far people will travel to have this condition properly addressed. Patients have come from every state in the US and from over 30 countries!


Dr. Stephen Wangen

Dr. Stephen Wangen is the co-founder and Medical Director of the IBS Treatment Center. He is a licensed and board certified physician with a doctoral degree in naturopathic medicine and a bachelor’s degree in biology, with honors. He is the award winning author of two books on solving digestive disorders, and a nationally recognized speaker. He has been seen and heard on ABC, NBC, and Fox as well as public radio and television. He was recently named one of Seattle’s Top Doctors by Seattle Magazine.

His passion for being a doctor and solving digestive problems comes from a lifelong obsession with optimizing health. Having suffered from IBS as a young man, Dr. Wangen dedicated his life to solving this complex problem. He now hand picks and oversees other fine doctors at the IBS Treatment Center for the new specialty of IBS medicine. Since 2005 the IBS Treatment Center, with locations in both Seattle and Los Angeles, has successfully helped thousands of patients from around the country and the world end their digestive problems. Learn more about Dr. Stephen Wangen.

Dr. Meredith Bull

Dr. Meredith Bull

Dr. Meredith Bull is fully licensed and certified with a doctoral degree in Naturopathic Medicine. Dr. Bull received her IBS specialty training under Dr. Wangen and, like all our providers, works closely with Dr. Wangen to provide the best care possible for IBS.

Dr. Bull is particularly interested in the mind-gut connection and recognizes the importance of digestive health on emotional well-being and vice versa.  Her primary goal in working with patients is to provide them with the knowledge and tools to regain control over their health so they can truly enjoy life.

In addition to expertise in digestive health, Dr. Bull has additional training in the health of older adults and helped co-author the first textbook in geriatric medicine, Integrative Geriatrics, published in 2017 as part of the Andrew Weil Integrative Medical Library.  She also has experiencing working with complex illnesses like Lyme disease.

Dr. Bull left a comfortable but unfulfilling previous life in finance to pursue a life-long interest in health and wellness and enjoys working at the IBS Treatment Center because of its patient-centered philosophy and sustainable healthcare model.  Originally from New Jersey, she has lived on the West Coast for over a decade and has called San Francisco, Seattle, and now Los Angeles home. She enjoys keeping active with hiking, yoga, and weight-lifting.

Dr. Lilla Diflorio

Dr. Lilla Diflorio

Dr. Lilla Diflorio is a long time resident of Los Angeles and a licensed and board certified doctor in both California and Washington, with a doctoral degree in Naturopathic Medicine. Dr. DiFlorio received her IBS specialty training under Dr. Stephen Wangen in Seattle, WA and has been with the IBS Treatment Center since 2017.

Dr. Diflorio is passionate about health care and enjoys working with her patients and watching them get healthier and get their lives back. As an IBS specialist Dr. Diflorio knows all too well that a happy digestive system is integral to both your physical and your mental health. and that healing the gut makes the whole person happy!

Dr. Diflorio is loved by both her patients and her team. Originally from Italy, Dr. Diflorio loves to garden and enjoys working in her family olive grove. She speaks fluent Italian and enjoys travel, good food and spending time with family. She received her bachelors of Fine Arts degree in drama from NYU, and in a previous life worked in the tv industry in Los Angeles.

Dr Pentland

Dr. Ken Pentland

Dr. Ken Pentland is an IBS specialist and a licensed and board certified physician with a doctoral degree in Naturopathic Medicine. Dr. Pentland trained under Dr. Wangen and has been working specifically with IBS patients at the IBS Treatment Center for over five years. His focus, passion for the job and sense of humor make him a special member of our team.

Dr. Ken Pentland has a personal history of digestive problems which he solved, so he knows what it’s like to be suffering with IBS. He is a firm believer that digestive wellness is at the root of whole health.

In a previous career Dr. Pentland worked as an engineer, having earned an Engineering degree from the University of Arizona. Therefore you can rest assured that he has a keen mind for sorting out complex problems. Dr. Pentland also enjoys playing classical guitar, backpacking, and spending time at home with his wife and two cats. Last but not least, Dr. Pentland has a Masters of Science degree in Acupuncture and Oriental Medicine.

Becky Rajcich RDN

Becky Rajcich, RD

Becky Rajcich is an IBS specialist nutritionist and a state and nationally certified Registered Dietitian Nutritionist, graduating with honors with a degree in Science of Nutrition. Becky’s food philosophy is that everyone has the right to eat food that supports their bodies and tastes good, and her expertise is in helping our IBS patients make their diets practical.

Becky specializes in taking challenging nutritional needs that can be overwhelming and breaking them down into simple, practical plans that can be incorporated into everyday life. She is also skilled at working with other dietary needs such as diabetes, weight loss, weight gain, disordered eating, low bone density, anemia, and other issues, integrating them with any food allergy or intolerance restrictions.

She brings compassion and commitment to her work with patients and finds joy in helping with them to get through nutrition challenges. Becky also enjoys running, reading, cooking, and recipe hunting; and she loves spending quality time with her husband, young son, dog, cat, and chickens. Patients and non-patients alike are eligible to schedule an appointment with Becky to work specifically on their nutritional and dietary needs.

Madison Service

Madison Service, RD

Madison Service is a Registered and nationally certified Dietitian Nutritionist, graduating with honors with a Bachelor’s degree in Nutrition from Colorado State University. She is an IBS specialist and works closely with all of the providers at the IBS Treatment Center. Madison believes the right kind of foods can be the most powerful form of medicine.

As someone who has personally experienced the debilitating effects of IBS, Madison particularly enjoys working with people who have digestive disorders and embraces the challenge of navigating restricted diets.  Working in partnership with the patient, she develops custom nutrition plans and menus tailored to meet individual needs of the client.  Inspired by her own personal journey, she enjoys supporting peoples’ health goals in a judgement-free, sensitive, and supportive environment through motivational coaching.   In addition to digestive wellness, she has experience providing nutritional guidance to those with diabetes, cardiovascular disease, weight management difficulties, and more.

Madison is committed to the success of her patients and strives to implement sustainable, realistic, and enjoyable dietary changes to enhance their quality of life.  In her free time, she is an adventure enthusiast and loves anything involving the outdoors including mountain biking, summitting peaks, and rock climbing.