Karen Halasan, MD

Dr. Mangla is a board-certified advanced gastroenterologist who specializes in diagnosing and treating a wide spectrum of gastrointestinal disorders. She believes in patient-centered care, allowing patient participation with a focus on access and communication. She is the only gastroenterologist in Connecticut who performs double balloon enteroscopy for small bowel evaluation. She is trained in advanced endoscopic procedures like treatment of barrett’s esophagus and early esophageal cancers using modalities like endomucosal resection, radiofrequency ablation (RFA), cryoablation and hybrid argon plasma coagulation (APC). Dr. Mangla also specializes in endoscopic ultrasound (EUS), utilized for evaluation of lesions in the liver, pancreas and bile ducts, as well as routine colonoscopies and endoscopies. As faculty, she enjoys teaching fellows in the training program.

Dr. Weir is a graduate of the Nova Southeastern University College of Osteopathic Medicine and performed his residency at Johns Hopkins University’ and Sinai Hospital. He completed pulmonary and critical care fellowships at Yale School of Medicine and Norwalk Hospital, as well as a sleep fellowship at Norwalk Hospital. He is board certified in pulmonary, critical care and sleep medicine. Dr. Weir is the program director for the Norwalk Hospital/Yale University pulmonary fellowship and Norwalk Hospital sleep fellowship. He specializes in the care of patients with breathing disorders, sleep problems and lung cancer. Dr. Weir treats patients ages 18+.

Mariana Bermeo is a dedicated and compassionate healthcare professional with a focus on gastroenterology. She holds a Master of Science in Family Nursing Practice from Fairfield University and she is certified by the American Academy of Nurse Practitioners. With a decade of experience as a Registered Nurse (RN), Mariana's journey in healthcare is marked by continuous growth and a deep understanding of patient needs. Her background as an RN has provided her with invaluable insights into patient care, making her a trusted advocate for health and wellbeing. Born in Romania, Mariana is fluent in both Romanian and Spanish.