“I partner with my patients and work with them to develop an individualized treatment plan based on their specific needs. My focus is patient-first, and my goal is always the best possible outcome for my patients. I believe that patients have a right to be informed of details about their conditions, prognosis, and possible modes of treatment. Once informed, patients have a much better chance in participating in a successful diagnostic and treatment plan. For me, empathy, trust, and honesty are key elements in the patient-physician relationship, and I work diligently to keep my patients well and satisfied.”

Board Certifications

  • Internal Medicine
  • Gastroenterology
  • Hepatology



Johns Hopkins Hospital
Gastroenterology, Hepatology, and Nutrition
Baltimore, MD

Internship and Residency

University of Texas Medical School at Houston
Internal Medicine
Houston, TX
1992 and 1994

Postgraduate Education

Poznan University of Medical Sciences
Doctor of Philosophy
Poznań, Poland

Medical School

Poznan University of Medical Sciences
Doctor of Medicine
Poznań, Poland

Hospitals Affiliated With

Houston Methodist West Hospital
Memorial Hermann Katy Hospital


“Membrane association of glutathione S-transferase mGSTA4-4, an enzyme that metabolizes lipid peroxidation products” Journal of Biological Chemistry, (2002): Singh, S.P., Janecki, A.J., Srivastava, S.K., Awasthi, S., Awasthi, Y.C., Xia, S.J., Zimniak, P.

“Basic fibroblast growth factor stimulates surface expression and activity of Na(+)/H(+) exchanger NHE3 via mechanism involving phosphatidylinositol 3-kinase” Journal of Biological Chemistry, (2000): Janecki, A. J., Janecki, M., Akhter, S., Donowitz, M.

“Subcellular redistribution is involved in acute regulation of the brush border Na+/H+ exchanger isoform 3 in human colon adenocarcinoma cell line Caco-2. Protein kinas…” Journal of Biological Chemistry, (1998): Janecki, A.J., Montrose, M.H., Zimniak, P., Zweibaum, A., Tse, C.M., Khurana, S., Donowitz, M.

Academic Appointments

Johns Hopkins Hospital
Instructor of Gastroenterology

University of Texas Medical School
Assistant Professor


Dr. Andrzej J. Janecki, a well-known and respected Gastroenterologist in Katy and West Houston, received his M.D. degree in 1977 in Poznan, Poland, and his Ph.D. degree in physiology in 1981. He completed his residency training in Internal Medicine at the University of Texas Medical School in Houston, and his fellowship training in Gastroenterology at Johns Hopkins Hospital in Baltimore. He has served as an Instructor of Gastroenterology at the Division of Gastroenterology at Johns Hopkins Hospital in Baltimore, Maryland, and as an Assistant Professor at the University of Texas Medical School in Houston, Texas. He is an author or co-author of over forty research articles and several book chapters.

Dr. Janecki is a Board Certified Gastroenterologist and Hepatologist. He practices general gastroenterology, hepatology, and nutrition and his special interests include inflammatory bowel diseases and diarrheal diseases. He spent the last 15 years practicing in the Katy area. He is an active staff member of Memorial Hermann Katy Hospital and Methodist West Houston Hospital.

Dr. Janecki enjoys spending time with his four children, listening to classical music, and photographing nature.

He has practiced in Katy for over 15 years and has a very large practice of loyal patients. He continues to take new patients as well.

Dr. Janecki has been voted “The Best Gastroenterologist in Katy” for the year 2016 by readers of Katy Living magazine.