MJ
34 Years of Experience
Accepting patients
Affiliated with a Castle Connolly Top Hospital
Who is Dr. Johnston, Gastroenterologist in Lancaster, PA?
Dr. Mark Johnston, MD is a Gastroenterologist, who primarily practices in Lancaster, PA with 2 additional practice locations. He has been practicing for over 34 years and is board certified by the American Board of Internal Medicine. Dr. Johnston graduated from Drexel University College Of Medicine and completed his residency at Nat'L Naval Med Ctr, Gastroenterology; Naval Reg Med Ctr, Internal Medicine. Dr. Johnston is fluent in English and Vietnamese, and is currently seeing new patients. Dr. Johnston’s practice accepts Medicare, UnitedHealthcare and other major insurance plans. To book an appointment or to confirm insurance options, please call Dr. Johnston’s office at (717) 431-3000.
Where did Dr. Johnston go to medical school and complete their residency?
Residency: Nat'L Naval Med Ctr, Gastroenterology; Naval Reg Med Ctr, Internal Medicine
Medical School: Drexel University College Of Medicine | HAHNEMANN UNIVERSITY COLLEGE OF MEDICINE
Is Dr. Johnston board certified in Gastroenterologist?
Yes, Dr. Mark Johnston, MD is board certified by the American Board of Internal Medicine
What languages does Dr. Johnston speak?
Dr. Johnston and their clinical team can communicate with patients in the following languages:
English
Vietnamese
What conditions does Dr. Johnston treat?
As a Gastroenterologist, Dr. Johnston diagnoses, treats, and manages a wide range of conditions. This condition information is derived from anonymized insurance claims and highlights the medical conditions most commonly treated by Dr. Johnston. It provides insight into the doctor’s areas of experience and expertise based on real-world patient encounters from the past two years, updated quarterly.
Also known as:
- Colon Cancer Screening
- Health Screening
- Colorectal Cancer Screening (PDQ®)
- Screening Tests to Detect Colorectal Cancer and Polyps
- Tests to Detect Colorectal Cancer and Polyps
- Colorectal Cancer Screening
- Colonoscopy Screening
- Bowel Cancer Screening
ICD-10 Codes:
- Z1211: Encounter for screening for malignant neoplasm of colon
Also known as:
- Acid Reflux
- GERD
- Acid Reflux (GER & GERD) in Adults
- Acid Reflux (GER & GERD) in Children
- Acid Reflux (GER & GERD) in Infants
- Gastroesophageal Reflux
- Heartburn
- Indigestion
ICD-10 Codes:
- K219: Gastro-esophageal reflux disease without esophagitis
Also known as:
- Colon Polyps
- History of Other Digestive System Disease
- Non-Infectious Gastroenteritis and Colitis
- Colonic Polyps
- Digestive Disease
- Colorectal Polyps
- Intestinal Polyps
- Bowel Polyps
- Past GI Disorder
- Previous Digestive Problem
- History of Gastrointestinal Illness
- Inflammation of Stomach and Intestines
- Non-Bacterial Colitis
- Gut Inflammation
ICD-10 Codes:
- Z86010: Personal history of colon polyps
- Z8719: Personal history of other diseases of the digestive system
- K529: Noninfective gastroenteritis and colitis, unspecified
Also known as:
- Upper Middle Abdominal Pain
- Widespread Abdominal Pain
- Abdominal Pain
- Epigastric pain
- Pain below breastbone
- Upper stomach pain
- General stomach pain
- Overall belly pain
- Diffuse abdominal pain
ICD-10 Codes:
- R1013: Epigastric pain
- R1084: Generalized abdominal pain
Also known as:
- Colon Polyps
- History of Adenomatous and Serrated Colon Polyps
- Colonic Polyps
- Colorectal polyps
- Bowel polyps
- Intestinal polyps
- Past Colon Polyps
- Previous Adenomas
- History of Precancerous Colon Growths
ICD-10 Codes:
- K635: Polyp of colon
- Z860101: Personal history of adenomatous and serrated colon polyps
Also known as:
- Nausea
- Nausea and Vomiting
- Feeling Sick to Stomach
- Queasiness
- Upset Stomach
- Feeling Sick and Throwing Up
- Stomach Flu Symptoms
- Queasy and Vomiting
ICD-10 Codes:
- R110: Nausea
- R112: Nausea with vomiting, unspecified
Also known as:
- Constipation
- Difficulty Passing Stool
- Infrequent Bowel Movements
- Hard Stools
ICD-10 Codes:
- K5900: Constipation, unspecified
- K5909: Other constipation
Also known as:
- Difficulty Swallowing
- Throat and Esophagus Swallowing Difficulty
- Swallowing Disorder
- Dysphagia
- Trouble swallowing
- Painful swallowing
- Pharyngoesophageal dysphagia
- Trouble swallowing in throat
- Esophageal swallowing problems
ICD-10 Codes:
- R1310: Dysphagia, unspecified
- R1314: Dysphagia, pharyngoesophageal phase
Also known as:
- Fluid in Abdomen
- Liver Disease
- Ascites
- Abdominal fluid buildup
- Peritoneal fluid
ICD-10 Codes:
- R188: Other ascites
Also known as:
- Rectal Bleeding
- Gastrointestinal Bleeding
- Gastrointestinal (GI) Bleeding
- Anal Bleeding
- Blood in Stool
- Lower GI Bleed
ICD-10 Codes:
- K625: Hemorrhage of anus and rectum
Also known as:
- Ulcerative Pancolitis
- Ulcerative Colitis
- Chronic Pancolitis
- Extensive Ulcerative Colitis
- Inflammatory Bowel Disease (IBD)
ICD-10 Codes:
- K5100: Ulcerative (chronic) pancolitis without complications
Also known as:
- Barrett's Esophagus
- Esophagus Disorder
- Barrett’s Esophagus
- Barrett's condition
- Esophageal metaplasia
ICD-10 Codes:
- K2270: Barrett's esophagus without dysplasia
Also known as:
- Diarrhea
- Loose stools
- Runny poop
- Frequent bowel movements
ICD-10 Codes:
- R197: Diarrhea, unspecified
Which procedures does Dr. Johnston perform as a Gastroenterologist?
As a Gastroenterologist, procedures performed by a Dr. Mark Johnston may include:
- Colonoscopy
- Colonoscopy Consultation
- Colorectal Cancer Screening
- Endoscopic Ultrasound
- Endoscopy / Endoscopic Ultrasound
- Gastric Balloon
- Gastric Stimulator Implantation Consultation
- Gastric Stimulator Implantation Follow Up
For detailed information, please contact Dr. Johnston's office.
Does Dr. Johnston accept my insurance?
Dr. Johnston accepts most major insurance plans. Important: Please call our office at (717) 431-3000 before your appointment to verify that your specific plan and network are accepted.
What insurance plans does Dr. Johnston accept in Lancaster, PA?
Dr. Johnston in Lancaster, PA accepts plans from many carriers. While this list is updated regularly, it is not a guarantee of coverage.
Top Insurances
Capital BlueCross
Centene
CVS Health (formerly Aetna)
Express Scripts
Geisinger Health Plan
Highmark Inc.
Independence Blue Cross
Medicare
UnitedHealthcare
UPMC Health Plan
View All Insurances
Where is Dr. Johnston's office located?
Dr. Mark Johnston's Primary Practice
2112 Harrisburg Pike Ste 202
Lancaster, PA 17601
(717) 431-3000
What is Dr. Johnston's NPI number?An National Provider Identifier (NPI) is a unique ID number that identifies doctors and healthcare providers nationwide.
Dr. Johnston's National Provider Identifier (NPI) number is 1003898131.
What common questions do patients ask about Dr. Johnston?
Here are answers to patients Frequently Asked Questions (FAQ’s) about Dr. Johnston
What is Dr. Mark Johnston's specialty?
Dr. Johnston is a Gastroenterologist near Lancaster, PA. An internist focused on diagnosing and treating disorders of the digestive system, encompassing the stomach, intestines, liver, and gallbladder. This specialist manages conditions like abdominal pain, ulcers, diarrhea, cancer, and jaundice, and performs intricate diagnostic and therapeutic procedures using endoscopes to examine internal organs. Contact Dr. Johnston to book an appointment today.
Is this Dr. Mark Johnston affiliated with a ranked Castle Connolly Top Hospital?
Yes, Dr. Johnston is affiliated with Penn Medicine Lancaster General Hospital which is a Castle Connolly Top Hospital. Castle Connolly Top Hospitals are healthcare institutions recognized for their excellence in specific medical procedures and overall patient care. They are identified through a rigorous peer nomination process, evaluating factors like patient outcomes, quality of care, and expertise. The list recognizes hospitals that excel in 20 or more specific medical procedures, representing the top 25% nationwide. Castle Connolly Top Hospitals
Where can I learn more about Gastroenterologist?
Explore Gastroenterologist with insights from trusted medical experts on EverydayHealth.com, where you'll find the most relevant content and helpful condition guides for up-to date information about symptoms, causes, diagnosis, treatment and more. See all our health guides to find trusted information on medical conditions from our experts at Everyday Health.
Is Mark Johnston accepting new patients in Lancaster, PA?
Yes, Dr. Mark Johnston is accepting new patients at this time.
Does Dr. Mark Johnston offer online booking?
Please contact Dr. Johnston's office at (717) 431-3000 for information about online booking, telehealth, or to schedule an appointment.
How can I make an appointment with Mark Johnston?
Please contact Dr. Johnston's office at (717) 431-3000 for information regarding telehealth appointment availability or for scheduling assistance.
Which board certifications does Dr. Mark Johnston have?
Dr. Mark Johnston is certified by the American Board of Internal Medicine.
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