Dr. Mark Saul Lowenheim, MD

I like Dr lowenheim. I just wish he would wash his hands or wear gloves when examining my toddlers genital region. That's my only complaint, otherwise I like this office for the most part.

Dr. Lowenheim is the best pediatric GI doctor I have ever had the pleasure of knowing. He is such a talented, dedicated, professional, accessible, & compassionate individual and his top priority is his patients. Dr. Lowenheim actually listens and addresses questions thoroughly and patiently. I am forever indebted to this man for helping my son and my family get through our darkest days related to my son's serious medical GI issues (as well as other health problems). I recommend him to any parents looking for the most qualified & caring pediatric gastroenterologist for their child.

Dr Lowenheim was the only doctor to find out the reason for my sons stomach pain. He suffered for 16 years and now he is pain free. He is a wonderful doctor and person.

He is rude, disrepectful. thinks he is doing you a favor instead of his job

We have been seeing Dr Lowenheim for many years now 19 almost!! my daughter was about 3 months old when we meet Dr "L" and his team at Stony Brook and she was a really sick little girl she was vomiting all the time would not eat or drink "really" I think with out Dr "L" helping us she would not be doing as good as she is now!!!! He has always gone out of his way to go over any of my Questions and work with us on ideas that seem to only work for Our child, during our time with Dr "L" my daughter was Diagnosised with a very rare syndrome Angelman Syndrome we along with him worked together to form a plan to help her and today 19 years latter she has come so far So Thank You Dr "L" you really are one of a kind and I would rate him AAAAA+++

My infant son was diagnosed with reflux by his regular pediatrician. After being prescribed Zantac for a few weeks I went back seeking an alternative treatment being the Zantac was not working.since my ped didn't want to change meds I sought out the help of a specialist. I found Dr. Lowenheim from a google search of gastro doctors in my area. At my first appointment the doctor was very short with me. He did a quick exam of my son and then just told me to increase the dose of Zantac and try a hypoallergenic formula. I don't even know what made him prescribe that being he conducted no tests and/or exams besides feeling his belly. I went home and booked a follow up appointment for 2 weeks. I tried the formula and the increased dose of Zantac during those two weeks. He also told me to bring a soiled diaper so he can test his stool at the next visit. In the two weeks between visits my sons symptoms didn't seem to improve whatsoever. I returned for my second appointment with soiled diaper… and all. Again the doctor turned came in did a quick 30 second exam sent me off with more Zantac and yet another formula both again which didn't help. He didn't answer any of my questions, or even take the soiled diaper for testing as he promised. I felt as if it were a COMPLETE and utter waste of time and he made me feel as if I were wasting my time but my money was good enough for him to rob from me on my 2 visits. $60 in copays later I am still stuck with a baby screaming and crying in pain from severe reflux. Dr. Lowenheim provided no answers and or advice. He was very cold, quick and arrogant with me. I do not think I am going to return for my third follow up visit. If you want to throw your money away and be treated like crap then he's the doctor to see if not keep looking and ask friends for some recommendations.

Great doctor! Recommend!!!!!