Mark Pimentel MD

Gastrointestinal Functional & Motility Disorders

Associate Professor, Medicine, UCLA School of Medicine

8700 Beverly BlvdLos Angeles, CA 90048
Phone+1 310-423-6143
Fax+1 310-423-8356

Dr. Pimentel is on Doximity

As a Doximity member, you’ll join more than three million U.S. healthcare professionals—including 85+% of physicians, and 2/3 of all NPs and PAs—in a private, secure network.

Gain access to free telehealth tools, such as our “call shielding” and one-way patient texting.
Connect with colleagues in the same hospital or clinic.
Read the latest clinical news, personalized to your specialty.

See Dr. Pimentel's full profile Already have an account?

Education & Training

UCLA David Geffen School of Medicine/UCLA Medical CenterFellowship, Gastroenterology, 1996 - 1999
University of ManitobaClass of 1992

The following disclaimer is related to board certifications obtained from ABMS®, denoted by the ABMS® logo.

This information is proprietary data maintained in a copyrighted database owned by the American Board of Medical Specialties®. The display and presence of ABMS Data in no way constitutes any affiliation, association with, or endorsement of any advertising, promotion, or sponsorship by ABMS and its affiliates and subsidiaries, the ABMS Member Boards, or ABMS board certified physicians and medical specialists. Copyright 2026 American Board of Medical Specialties®. All rights reserved.

The user is responsible for ensuring that the profile obtained in this directory is the profile of the physician or medical specialist being sought.

A self-designated specialty, subspecialty, or practice area neither implies nor is equivalent to ABMS board certification or the existence of specialized training by or competence of a physician or medical specialist.

Certifications & Licensure

CA State Medical License 1996 - 2027

Awards, Honors, & Recognition

CMS Meaningful Use Stage 2 Certification EpicCare Inpatient 2014 Certified EHR Suite (with Beaker), Epic Systems Corporation, 2014, 2016-2017
CMS Meaningful Use Stage 2 Certification Beacon Oncology 2014 Certified Module, Epic Systems Corporation, 2014, 2016-2017
CMS Meaningful Use Stage 1 Certification EpicCare Ambulatory 2014 Certified EHR Suite, Epic Systems Corporation, 2014, 2016-2017

Clinical Trials

Rifaximin for the Treatment of Irritable Bowel Syndrome
COMPLETED
PHASE2
Neomycin and Rifaximin Plus Neomycin in Treating Methane Positive Constipation Predominant Irritable Bowel Syndrome
COMPLETED
NA
Pilot of AbStats /AEGIS System for Detecting Motility Abnormalities
COMPLETED

Publications & Presentations

PubMed

Do Multi-Omics Approaches Improve the Diagnosis of Microbial Overgrowth Syndromes?
Juliana de Freitas Germano, Gabriela Leite, Mark Pimentel
Current Gastroenterology Reports. 2026-09-07
Duodenal microbiome profiles exhibit sex-specific differences.
Mohamad Rashid, Gabriela Leite, Gillian M Barlow, Ava Hosseini, Daniel Brimberry
Iscience. 2026-08-21
End Point Discordance in Irritable Bowel Syndrome With Constipation: Bloating as a Partially Uncaptured Therapeutic Signal.
Jonathan A Busam, Mark Pimentel
Clinical Gastroenterology and Hepatology. 2026-08-16

Journal Articles

Declining Rates of Referral for Irritable Bowel Syndrome Without Constipation at a Tertiary Care Center
Nipaporn Pichetshote, Vartan C Tashjian, Mark Pimentel, Ali Rezaie, Ruchi Mathur, Digestive Diseases and Sciences

Lectures

Influence of Dietary Restriction on Irritable Bowel Syndrome
Los Angeles, CA - 6/15/2014
Breath Testing
AGC 2018 Annual Scientific Meeting, Philadelphia, PA - 10/8/2018
Case-Based Functional GI Testing: Ask the Experts
AGC 2018 Annual Scientific Meeting, Philadelphia, PA - 10/8/2018

Press Mentions

Welcoming Dr. Millie Long as ACG Institute DirectorOctober 10th, 2026
Cedars-Sinai Experts Highlight Digestive Health AdvancesOctober 24th, 2025
Microbiome Highlights from Digestive Disease Week 2025September 8th, 2025

Professional Memberships

Endocrine Society - ENDO
Member

Viewing the full profile is available to verified healthcare professionals only.

Find your profile and take control of your online presence:

Similar Physicians & HCPs

Simon Lo, MD
GILos Angeles, CA
Maria Abreu, MD
GIWest Hollywood, CA
Mamatha Sadda, MD
GILos Angeles, CA
Derek Cheng, MD
GILos Angeles, CA
Christopher Almario, MD
GILos Angeles, CA
Bianca Chang, MD
GIWest Hollywood, CA
Kenneth Park, MD
GILos Angeles, CA
Phillip Gu, MD
GIWest Hollywood, CA
Ali Rezaie, MD
GIWest Hollywood, CA
Rashmi Advani, MD
GIWest Hollywood, CA

Doximity / States / California / Los Angeles / Mark Pimentel, MD

Dr. Mark Pimentel, Dr. Mark Pimentel, MD, Dr. M Pimentel