Colonoscopy clinicians in Lexington, Kentucky

CMS lists 39 clinicians with a primary specialty of Gastroenterology, Internal Medicine, Family Practice, or General Practice who have billed Medicare for at least one colonoscopy and practice in Lexington, Kentucky (details below).

Colonoscopy volume

Clinician	Colonoscopies billed	Percentile rank
An-Yu Chen, MD	177	85%
Todd Horn, MD	169	84%
Matthew Ashmun, MD	154	81%
Adalberto Castellanos, MD	125	73%
June Yong, MD	122	72%
Stephen Schindler, MD	116	70%
Nathan Massey, MD	106	66%
James Pezzi, MD	106	66%
Kathleen Martin, MD	90	60%
John Brown, MD	85	57%
Gregory Woolfolk, MD	85	57%
Warren Frank, MD	75	52%
Scott Merkley	73	51%
Mark Brunner, MD	58	44%
Deborah Flomenhoft, MD	57	43%
Courtney Perry, DO	55	42%
Damir Kusmic, MD	47	37%
Victor Howard	43	34%
Ruben Plentz, MD	36	30%
Donald Campbell, MD	35	29%
Bahaaeldeen Ismail, MD	34	29%
Joseph Auer	32	27%
Marijeta Pekez, MD	32	27%
Terrence Barrett, MD	31	27%
Venkata Rajesh Konjeti, MD	27	24%
Jens Rosenau, MD	23	22%
Brooks Richardson, MD	21	20%
Christina Leyson, MD	14	15%
Donald Rauh, MD	13	15%
Ujasbhai Patel, MD	12	14%
Ingrid Beyruth Schwartz, MD	1-10	13% or below
Lanla Conteh, MD	1-10	13% or below
Darwin Conwell, MD	1-10	13% or below
Alla Grigorian, MD	1-10	13% or below
Laurie Haas, MD	1-10	13% or below
Samuel Mardini, MD	1-10	13% or below
Steven Shedlofsky, MD	1-10	13% or below
Mark Spurlin, MD	1-10	13% or below
Kshitij Thakur, MD	1-10	13% or below

Sorted by the number of colonoscopies billed to Medicare, highest first, not by quality or skill. CMS suppresses counts between 1 and 10 to protect patient privacy and publishes the range instead.

Understanding CMS Data

CMS's "Colonoscopy" category combines specific billing codes for colonoscopy to calculate the number of times each clinician billed Medicare for a "Colonoscopy." These include screening colonoscopy, diagnostic colonoscopy, and colonoscopy with biopsy or polyp removal. CMS's list also includes flexible sigmoidoscopy and laparoscopic appendectomy, so a clinician's count may include those procedures. CMS counts one procedure per patient per day, so a colonoscopy that included both a biopsy and a polyp removal counts once. CMS reports only procedures that clinicians billed to Original Medicare and Medicare Advantage. Therefore, CMS's procedure volume data does not include procedures that clinicians may have performed on patients who have other health care coverage (e.g., commercial insurance, self-pay, or the VA). Billing variation and coding errors can also affect CMS's data. Therefore, the number of procedures that CMS reports for a clinician may be higher or lower than the actual number of colonoscopies a clinician performed during the reporting period. Lastly, only clinicians with a primary specialty of Gastroenterology, Internal Medicine, Family Practice, or General Practice (as reported to Medicare) are presented.

Source: Centers for Medicare & Medicaid Services (August 18, 2026 release).