https://www.sunydownstatepediatricgastroenterology.org/home daily 1.0 2025-06-26 https://www.sunydownstatepediatricgastroenterology.org/services daily 0.75 2024-07-26 https://www.sunydownstatepediatricgastroenterology.org/fellowship-training daily 0.75 2025-07-22 https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/767c14a8-5df5-4264-861d-e2c7746a7b4f/thumbnail_IMG-5805.jpg Fellowship Training - Fellowship Training Our team of nationally renowned attendings are dedicated to the education and mentorship of our fellows in training. We support a diverse group of physicians with individualized mentoring, creating an environment of scientific inquiry and skill. The ACGME-accredited Pediatric Gastroenterology, Hepatology and Nutrition fellowship offers a three-year program that teaches endoscopic proficiency and expertise in patient care. The program also offers excellent research opportunities leading to publication in established journals, with our fellows averaging 3 publications during their tenure. Notable aspects: We have a collaborative relationship with NYU, completing 1 month of hepatology training there during the 2nd year, as well as maintaining a monthly hepatology clinic at Kings County. We are a leader in pediatric GI global health and health disparities research, with ongoing collaborations with the Downstate School of Public Health, opportunities for further training (MPH, Epidemiology, etc), and existing projects with the University Teaching Hospital of Lusaka, Aga Khan University in Karachi, and many other sites around the world. We operate the only IBD center in Brooklyn, with capacity for IBD Ultrasound, our own inherent infusion resources, and an active research environment under the leadership of Dr. Annie Levine. We operate the only academically integrated inpatient pediatric feeding unit on the East Coast, with an innovative one week structure and collaboration with our developmental pediatric team to drive full evaluation and implementation of all available services, while still remaining accessible to low income families who cannot afford a 1 month long treatment. We have established a strong AI/ML lab core, with inherent supercomputing resources and institutional knowledge to support further work. Board passage: currently 100% We provide comprehensive pediatric GI coverage in Brooklyn, covering Downstate University Hospital and Kings County Medical Center. We also offer satellite clinics in Coney Island and Staten Island. https://www.sunydownstatepediatricgastroenterology.org/appointments daily 0.75 2021-09-30 https://www.sunydownstatepediatricgastroenterology.org/publications daily 0.75 2025-03-21 https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/1632407959955-Z0VLOCO1CLZDL5Q83UFC/duox+stain+website.png Publications - Notable Publications Joseph M, Steinberg J, Mark JA, Wallach T, Nguyen N. Economic Benefit of Implementation of Pediatric Transnasal Endoscopy in Eosinophilic Esophagitis. Clin Gastroenterol Hepatol. 2025 Mar 6:S1542-3565(25)00153-3. doi: 10.1016/j.cgh.2025.01.011. PMID: 40057008. Wallach T, Zhu K, Vega V, Sharma S, Brown J. Pilot Study of Fecal Mitochondrial DNA in Inflammatory Bowel Disease Patients Demonstrates a High Sensitivity Assay with Likely Capacity to Differentiate between Disease and Histologic Remission. Gastro Hep Advances Lu P-T, Mahar AR, Sitt H, Rosenbaum J, Bargman R, Wallach T. The expanded Child Tax Credit was associated with improved BMI and metabolic outcomes in low-income children. JPGN. 2024; 1-3. doi:10.1002/jpn3.12445 Villalba-Davila P, Aronson S, Lat J, Charles C, Schroeder B, Pittman M, Tang V, Wallach T. Helicobacter pylori infection is associated with significant elevations to fecal calprotectin, systemic inflammatory markers. JPGN 2025 Jan 20. doi: 10.1002/jpn3.12464. PMID: 39831651. Miller L, Cho H-G, Banayan C, Vega Lemus V, Sharma S, Wallach T. Achalasia in Klinefelter syndrome: a suspected pediatric case as well as prevalence analysis suggesting increased risk in this population. JPGN Rep. 2024; 1-3. doi:10.1002/jpr3.12084 Arostegui, D., Armaly, P., Castro Ochoa, K., Lemus, V.V., Peshimam, J., Sharma, S., Schwarz, S. and Wallach, T. (2023), Pilot Study of Ondansetron in Improvement of Pediatric Colonoscopy Preparation Outcomes at an Urban Academic Center. JPGN Reports, 4: e366. https://doi.org/10.1097/PG9.0000000000000366 Luo, Yan; Fu, Yinan; Schwarz, Steven; Wallach, Thomas. Comparison of Risk and Severity of Helicobacter Pylori Infection in Non-Native Versus US Native Pediatric Patients. JPGN Reports (3):p e331, August 2023. | DOI: 10.1097/PG9.0000000000000331 Rabinowitz SS. Putting the Patient Back into Patient Advocacy. J Pediatr Gastroenterol Nutr. 2023 Nov 1;77(5):577-578. doi: 10.1097/MPG.0000000000003926. Epub 2023 Aug 24. PMID: 37612803. Rosenbaum JE, Ochoa KC, Hasan F, Goldfarb A, Tang V, Tomer G, Wallach T. Epidemiologic Assessment of Pediatric Inflammatory Bowel Disease Presentation in NYC During COVID-19. J Pediatr Gastroenterol Nutr. 2023 May 1;76(5):622-626. doi: 10.1097/MPG.0000000000003740. Epub 2023 Feb 19. PMID: 36805627; PMCID: PMC10097471. Rabinowitz SS, Yu L, Geraghty P. EoE behaves as a unique Th2 disease: a narrative review. Transl Gastroenterol Hepatol. 2023 Jan 25;8:11. doi: 10.21037/tgh-22-15. PMID: 36704651; PMCID: PMC9813655. Castro K, Samant S, Liu A, Duysburgh C, Marzorati M, Singh P, Hachuel D, Chey W, Wallach T. In-Vitro Efficacy of Targeted Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols Enzymatic Digestion in a High-Fidelity Simulated Gastrointestinal Environment. Gastro Hep Advances 2022, October 2;3 283-290. doi https://doi.org/10.1016/j.gastha.2022.10.011 Kummerlowe C, Mwakamui S, Hughes TK, Mulugeta N, Mudenda V, Besa E, Zyambo K, Fleming I, Vukovic M, Doran B, Bramante JT, Uchida AM, Garber JJ, Ordovas-Montanes J, Gartner Z, Shalek AK, Kelly P, Wallach T. “Single-cell profiling of environmental enteropathy reveals signatures of epithelial remodeling and immune activation in severe disease.” Science and Translational Medicine, 2022 Zhu KJ, Suttner B, Knee J, Capone D, Moe CL, Stauber CE, Konstantinidis KT, Wallach TE, Pickering AJ, Brown J. “Elevated fecal mitochondrial DNA from symptomatic norovirus infections suggests potential health relevance of human mitochondrial DNA in fecal source tracking” Environmental Science & Technology Letters, 2022 Arostegui D, Castro K, Schwarz S, Vaidy K, Rabinowitz S, Wallach T. “Persistent SARS-CoV-2 Nucleocapsid Protein Presence in the Intestinal Epithelium of a Pediatric Patient 3 Months After Acute Infection”. JPGN Reports, 2022 Castro K, Arostegui D, Schwarz S, Gandhi S, Peshimam J, Rabinowitz S, Pittman M, Wallach T. “Histologically Remarkable Eosinophilic Esophagitis Responsive to Dupilumab in a Gastrostomy Tube Dependent Pediatric Patient on Amino Acid Formula." JPGN Reports, 2022 Rabinowitz SS, Feng L, Ebigbo N, Lin B, Gupta R, Sklar R, Grossman E and Schwarz SM, Weedon J, Gress F. Predicting pediatric esophageal wall thickness: An EUS study. Endosc Ultrasound 4; 259-266, 2020 Ahuja N, Weedon J, Schwarz SM, Sklar R and Rabinowitz SS. Applying the eosinophilic esophagitis reference scores to different aged children. J Pediatr Gastroenterol Nutr 71; 328-332, 2020. Vaidy K, Winderman R, Rabinowitz SS and Schwarz SM. Treatment of pyoderma gangrenosum in pediatric inflammatory bowel disease. JPGN Reports 1; e008, 2020. Winderman R, Rabinowitz SS, Vaidy K and Schwarz SM. Measurement of microvascular function in pediatric inflammatory bowel disease. J Pediatr Gastroenterol Nutr 68; 682-688, 2019. Saghier S, Schwarz SM, Anderson V, Gupta R, Heidarian A, Rabinowitz SS. Pediatric Helicobacter pylori gastropathy demonstrates a unique pattern of gastric foveolar hyperplasia. Helicobacter 2018 Apr 25:e12487. doi: 10.1111/hel.12487. Windemuller F, Xu J, Rabinowitz SS, Hussain MM and Schwarz SM. Lipogenesis in Huh7 cells is promoted by increasing the fructose:glucose molar ratio. World J Hepatol 8: 838-843, 2016. D’Souza A, Algotar A, Pan L, Schwarz SM, Treem WR, Valencia V and Rabinowitz SS. Packed red blood cell transfusions as a risk factor for parenteral nutrition associated liver disease in premature infants. World J Clin Pediatr 8; 365-369, 2016. Vo HD, Goli S, Gill R, Anderson V, Stefanov D, Xu J, Kulsum-Mecci N, Schwarz SM and Rabinowitz SS. Inverse correlation between Helicobacter pylori colonization and obesity in a cohort of inner-city children. Helicobacter 20: 64-68, 2015. Vo HD, Sequeira J, Quadros EV, Schwarz SM and Perenyi A. The role of folate receptor autoantibodies in preterm birth. Nutrition 10: 1224-227, 2015. https://www.sunydownstatepediatricgastroenterology.org/faculty daily 0.75 2024-10-31 https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/3ccf0cf7-b007-4266-980d-8f470cde45ca/First+choice+%281%29.jpeg Faculty Thomas Wallach, MD Chief of Pediatric Gastroenterology/Pediatric GI Fellowship Director Dr. Thomas Wallach is a physician scientist and pediatric gastroenterologist currently taking new patients. Video introduction and informational videos are available here. Training: Dr. Wallach attended Pomona College, and completed his medical education at the Medical College of Wisconsin. He then completed a pediatric residency at Columbia University right here in New York, followed by an extended research fellowship in Pediatric Gastroenterology at the University of California, San Francisco, where he engaged in research focused on the regulation of the intestinal epithelial barrier, as well as advanced training in pain medicine. Expertise: Dr. Wallach is an expert on diseases of the intestinal epithelial barrier, with a specific focus on diseases of gut-brain interaction like irritable bowel syndrome, or other non-inflammatory causes of abdominal pain. Having trained at UCSF, a preeminent research site in inflammatory bowel disease and liver transplant center, he also has notable expertise in IBD, celiac disease, and liver diseases. Special Services: Acceptance and Commitment Therapy, IB-Stim trans-auricular therapy for abdominal pain, pain management https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/d555d9cb-e307-4e6c-a0e8-f6bf2e8b8c2b/image_processing20221005-97175-2zhf90.jpeg Faculty Annie Levine MD Director - IBD Clinic Dr. Annie Levine is our inaugural IBD Clinic director, with a practice focused primarily on diagnosis, management, and research into pediatric inflammatory bowel disease. She also holds general clinics at Downstate, Kings County, and Coney Island. She is accepting new patients. Training: Dr. Levine received her BA in Slavic Languages from Harvard University. She attended medical school at the University of Pittsburgh, and complete a pediatric residency at Brown University. Her Pediatric Gastroenterology training was completed at Seattle Children’s Hospital. Expertise: IBD (Ulcerative Colitis, Crohn’s Disease), general gastroenterology, genomics. Special Services: Capsule Endoscopy https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/1632853731041-SO2JW1DVQPYWSXFCMXKH/Simon.jpg Faculty Simon Rabinowitz, MD, PhD Director - Inpatient Feeding Therapy Unit Simon S Rabinowitz, PhD MD has been the Vice Chairman of Pediatrics at Downstate for ten years while he continues to see new patients with gastrointestinal, hepatic, pancreatic, or nutritional complaints. He is currently taking new patients. Training: Dr. Rabinowitz grew up in Brooklyn, and after graduating from Stuyvesant High School and Vassar College, he earned his PhD in Biochemistry at the University of Wisconsin, Madison. He completed his education in the PhD to MD program in Miami in 1983. He returned to NYC where he did his Pediatrics and his Pediatric Gastroenterology training at Mt Sinai. Career: Dr. Rabinowitz served as the founding director of Pediatric Gastroenterology, Hepatology, and Nutrition at Downstate in 1987. After leading the Downstate division for 12 years, he was recruited to LICH as the Vice Chair of Pediatrics and then became the Chairman of Pediatrics and Program Director for the Pediatric residency at St Vincent, Staten Island from 2003-2011. Throughout these years he maintained an active practice, attracting challenging children with digestive and nutritional diseases to share with his trainees. He has written about failure to thrive. malnutrition, gastroesophageal reflux, gastritis, Hepatitis C, intestinal polyps, and eosinophilic esophagitis. Recognition: Dr. Rabinowitz’s expertise has been recognized by New York Magazine, Castle Connolly, Who’s Who in Medicine, and others for the quality of his work. He is a fellow of the American Academy of Pediatrics and the American Gastroenterological Association and has consistently taught young doctors an empathetic approach to their patients. He specializes in children with complicated problems who are in need of a diagnosis, or of a second opinion to improve their growth or quality of life. Special Services: Endoscopic Ultrasound, ongoing studies in eosinophilic esophagitis. https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/1628035595346-PY0KDVZUDDN4LP8URK5H/steve.jpg Faculty Steve Schwarz, MD Dr. Steve Schwarz is a distinguished clinician with decades of experience. Dr. Schwarz is a highly decorated provider, having previously been awarded the American Academy of Pediatrics Charles Murray award recognizing an outstanding clinician, educator, and scientist who has made significant contributions to the field of pediatric gastroenterology and nutrition. Dr. Schwarz is generally not taking new patients, but is available for consultation upon request. . Training: Dr. Schwarz attended Yale University, followed by completing his medical education and Pediatric Residency at Columbia University. He completed gastroenterology fellowships at Stanford University and Columbia University. Expertise: Dr. Schwarz has practiced, researched, and led the field of pediatric gastroenterology for decades. He has broad expertise in nutrition, inflammatory disease, and allergic disease. https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/a6b05356-0d73-493a-a8fd-c86261c31c97/radhanathan.jpg Faculty - Radha Nathan, MBBS Dr. Nathan is a part time faculty member splitting time between Kings County Medical Center and Brookdale Hospital. She has specific interests in constipation, milk protein intolerance, failure to thrive, and pediatric reflux. https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/78a964ba-081f-4cc6-b9ff-e7781fae00cb/ahlawat.jpg Faculty - Sushil Ahlawat, MD, MS, MBBS, FACP, FASGE, AGAF Chief - Division of Gastroenterology/Hepatobiliary and Advanced Endoscopy Specialist Dr. Ahlawat is board certified in Internal Medicine, Gastroenterology and Transplant Hepatology. He is a trained interventional gastroenterologist with expertise in advanced endoscopic procedures. He specializes in endoscopic retrograde cholangiopancreatography (ERCP), diagnostic and interventional endoscopic ultrasound (EUS), endoscopic mucosal resection/polypectomy, endoluminal stent placement and deep small bowel enteroscopy. His specialty training includes a fellowship in Gastroenterology and Hepatology at Georgetown University School of Medicine in Washington, DC, and an advanced fellowship that focused in Therapeutic Endoscopy at Georgetown University School of Medicine in Washington, DC. He also completed a fellowship in Advanced Medicine at Mayo Clinic College of Medicine, Rochester, MN. He earned his medical degrees from Postgraduate Institute of Medical Sciences in Rohtak (India) and M.S. (Clinical Research) from Mayo Clinic College of Medicine in Rochester, MN. He completed his internal medicine residency at Montefiore Medical Center in New York, NY. Dr. Ahlawat is available for pediatric patients older than 2 years of age requiring ERCP for gall stones, chronic pancreatitis, or other relevant indications. https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/2e2de859-543d-425a-afb8-ee4e61a4e944/Stepan.JPG Faculty Shannon Stepan, PhD Dr. Stepan works with the Pediatric GI division to support patients with comorbid pain syndromes, anxiety, or depression, which are common complications of chronic illness. She specializes in short and long-term psychotherapy aimed at increasing self-awareness and identifying patterns in thinking and behavior that contribute to mood symptoms and chronic pain. Dr. Stepan is able to provide her services to our patients via telehealth, and free of charge. Training: Dr. Stepan earned a Doctorate in Clinical Psychology from The New School. Her doctoral research focused on child well-being and its relationship with parents’ representations of attachment. She trained in outpatient and inpatient settings in several New York City hospitals, including Maimonides Medical Center, LIJ Medical Center, Woodhull Medical Center, and Mt. Sinai Beth Israel. She completed my clinical internship at Maimonides Medical Center and also served as a Research Associate in the Psychiatry Residency program there. https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/b64735bf-7d22-4c3c-9761-91c7313ddd15/Vittorio.JPG Faculty - Jennifer Vittorio, MD Director - KCH/NYU Hepatology Outreach Clinic Dr. Jennifer Vittorio is a pediatric transplant hepatologist, serving as the director of the Kings County Pediatric Liver Clinic, and the Course Director of our fellowship hepatology training at New York University. Training: Dr. Vittorio is the Medical Director of Pediatric Liver Transplant at NYU. She completed her medical school and pediatric residency at Georgetown University, and her fellowship in pediatric gastroenterology and transplant hepatology at Columbia University. She is an expert in liver disease, transplant management, and publishes extensively in clinical research regarding transplant and liver disease. https://www.sunydownstatepediatricgastroenterology.org/inpatient-feeding-program daily 0.75 2025-10-24 https://images.squarespace-cdn.com/content/v1/5ec321c2af33de48734cc929/1618497259178-6XJGK9GR6YAVBQL5L519/20140301_Trade-151_012-2.jpg Inpatient Feeding Program https://images.squarespace-cdn.com/content/v1/5ec321c2af33de48734cc929/1607694583486-2PQT0LQ193RL7MCB6DX4/20140228_Trade+151_0046.jpg Inpatient Feeding Program https://www.sunydownstatepediatricgastroenterology.org/nygc daily 0.75 2026-03-04 https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/1728505763399-PCLBYEPJ7R9OKTE4RGG3/unsplash-image-C4G18Paw0d4.jpg https://www.sunydownstatepediatricgastroenterology.org/support-us daily 0.75 2025-12-09 https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/5ad94f16-cbcc-4f43-ac2a-45e6b0fc21e7/schwarz.JPG https://www.sunydownstatepediatricgastroenterology.org/get-started daily 0.75 2025-05-08 https://www.sunydownstatepediatricgastroenterology.org/eats-streets-and-beets daily 0.75 2025-09-26 https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/5809ee20-7a04-4478-8c01-c2c1207f6be1/a+poster+for+a+block+party+and+nutrition+conference+in+flatbush%2C+brooklyn%2C+hosted+by+SUNY+downstate+%2814%29.png https://www.sunydownstatepediatricgastroenterology.org/peds-gi-av-club daily 0.75 2025-07-02 https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/7409389c-388b-4aca-96bb-c3e932ec0f25/StevenSchwarz_4x5_6810.jpg https://images.squarespace-cdn.com/content/v1/610801c120aaf57180ce0cc1/4998fb9c-e532-4e78-aba1-9fd692c68135/logo-full-14299a7d91e851e67290dfd2fb0938ba613a50d391a3bf8667bdcdf5173d29e0.png