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At the Clinic

Procedures and Treatments:

Barrett’s Esophagus
Ulcerative Colitis
Colon cancer detection
Irritable Bowel Syndrome
Digestive Tract Treatments
Digital Chromoendoscopy
Early Detection of Cancer
Esophageal Blockage
Gastric Ulcers
Gastrointestinal Hemorrhage
Helicobacter pylori
High-resolution Video Endoscopy
Liver - Hepatitis
Reflux Disease
Resection of Gastric Polyps
Sclerosis and Ligature of Esophageal Varices
Gastric Cancer

Doctor's Profile

GASTRO, S.A. is a group of six gastroenterology specialists located on the 8th floor of the Multimedica Building in zona 15 of Guatemala City. They have a various clinics, offices and treatment centers with the latest endoscopic and laser technology to care for their patients to the highest global standards available. An on-site pharmacy assures that patients receive proper medications and dosage instructions.

This profile section includes information about each doctor’s medical background, unique talent, bi-lingual skills and continuing education.

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Dr Alejandro Hernandez Monroy has performed over 20,000 medical procedures during his career, since the mid-1980’s. He speaks English for the convenience of North American patients, and learned Japanese during his specialty training in Kobe, Japan. His primary devotion is to early detection and treatment of cancers of the digestive system.

Dr. Hernandez is devoted to treating each patient with human warmth, prompt efficiency and diagnostics that can make the difference in bringing fast and effective treatment, offering better quality of life at a reasonable cost. He is well-respected as being ethical, responsible and experienced. Dr. Hernandez lists running, soccer and tennis among his favorite activities for staying fit.

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Dr. Dulis Velasquez Miranda speaks English and German in addition to Spanish, and has been in private practice in Guatemala City since the late-1980’s.

Dr. Velasquez knows that patients are motivated to continue with a treatment program if they are well-informed and actively included in the decision-making process. The doctor carefully considers every step of the plan to conclude the best course of treatment: minimally invasive, and highly effective. His patients can be certain of receiving proper treatment with compassion, respect and the high quality scientific instrumentation that assures success.

Some highlights of the education and profession affiliations of Dr. Velasquez:

  • Asociación Guatemalteca de Gastroenterología, Hepatología y Endoscopia Gastrointestinal: presidente, 2007-2009
  • Centro Médico Militar. Miltary Medical Center of Guatemala. Jefe de la Sección de Gastroenterología. Head of the Gastroenterology Department
  • Ruprecht-Karls-Universitat, Heidelberg, Germany: Gastroenterology, Hepatology
  • Hospital Oststadt, Hannover, Niedersachsen, Germany: Gastrointestinal Endoscopy & Hepatology Research Studies.
  • Universidad of San Carlos, Guatemala: Medico y Cirujano, Physician and Surgeon

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Dr. Pedro Vinicio Méndez speaks English and Japanese for the convenience of his international patients.

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Dr. Javier Fernandez de Paz

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Dr. Jorge Chang Maryorga

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Dr. Leopoldo Sajche Valladares

Professional Affiliations

Kendal Regional Medical Center, Miami Florida, USA.

  • International Exchange Award granted to “GASTRO S.A.” Guatemala City, 2005.
  • Premio de Intercambio Internacional Otorgado a GASTRO, SA, 2005.

Asociación Guatemalteca de Gastroenterología, Hepatología y Endoscopia Gastrointestinal.

  • Dulis Velasquez. Presidente, 2007-2009
  • Pedro Vinicio Méndez. Diploma, Avanzas en Gastroenterología, 2005.
  • Pedro Vinicio Méndez. Socio Activo desde 2005.

Asociación de Cirujanos de Colon y Recto de Guatemala.

  • Pedro Vinicio Mendez, Miembro Corespondiente desde 2002.

Japan Gastroenterological Endoscopy Society – JGES.

  • Pedro Vinicio Mendez. Gastroenterological Endoscopy Training, 1996

Asociación Puertorriqueña de Gastroenterología – APG.

  • Alejandro Hernández

American Gastrointestinal Association – AGA.

  • Alejandro Hernandez

Congreso Europeo de Gastroenterología, Madrid, España.

  • Alejandro Hernandez

Academic Affiliations

Universidad de San Carlos – USAC, Guatemala.

  • Alejandro Hernández
  • Dulis Velásquez
  • Pedro Vinicio Méndez

Kobe University, Japan.

  • Alejandro Hernandez

Tokyo Medical and Dental University, Tokyo, Japan.

  • Pedro Vinicio Mendez. Training course in Gastroenterology, 1996.

Ruprecht-Karls-Universitat, Heidelberg, Germany: Gastroenterology, Hepatology.

  • Dulis Velasquez

Hospital Oststadt, Hannover, Niedersachsen, Germany: Gastrointestinale Endoskopie und Hepatologie Forschungsstudien. Gastrointestinal Endoscopy & Hepatology Research Studies.

  • Dulis Velasquez.

Showa University, Fujigaoka Hospital, Japan

Dr. Pedro Vinicio Mendez. Intensive course in ERCP, ESP and Diagnostic Endoscopy, 1996. Curso Intensivo en endoscopia de vesícula biliar, sistema biliar, páncreas e hígado.


Dr. Javier Fernandez, GASTRO, SA
Dr Alejandro Hernandez, GASTRO, SA
Dr. Dulis Velasquez, GASTRO, SA
Dr. Jorge Chang, GASTRO, SA
Dr. Leopoldo Sanjche, GASTRO, SA
Dr Mendez en you tube, GASTRO, SA
Who Is at Risk for Colon Cancer?
What happens during a colonoscopy?



Please write to us about your experience with the doctor in the “Comments” section below. Other patients will be interested to know more about the doctor’s skill, experience, ethics and personal attention, as they resulted in your successful outcome.

The whole experience of meeting with Dr. Mendez and having my endoscopy was prompt, efficient and professional. The doctor spent plenty of time to investigate all my symptoms, then come up with the right answer for a solution. We scheduled an endoscopy the next day, with a CD of the entire procedure and a written report delivered to me, the doctor and my GMT medical advocate that afternoon. That would never happen in the United States!

Bottom line: I’m 90% better two weeks later and grateful to call Dr. Pedro Mendez my new “go to” doctor for anything gastro-related.

Mrs. King, Antigua Guatemala, 2018

Peer Reviews From Other Doctors

Read here what other doctors have to say about this doctor.

Charity, Public Service, Donations

Public service and caring for the less fortunate is a way of life in the Latin American culture.


Vidas Plenas is a charity that provides medical, economic and spiritual support for children who are orphaned or at risk in Guatemala City. Dr. Hernandez offers his medical skills and generous heart with the goal of providing these children with the motivation to develop a better life of good health and happiness.

Dr. Hernandez performs low-cost procedures at the public hospitals for patients who could otherwise afford that level of medical attention.