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Gastrointestinal & digestive diseases

Breaking down the barriers to gastrointestinal testing

Despite the importance of early detection for colon cancer, inflammatory bowel disease, and other gastrointestinal conditions, many patients are resistant to testing due to concerns with the preparation and procedures involved with these vital screenings.

Recognizing these barriers, Quest Diagnostics offers an extensive menu of minimal-prep testing that preempts patient hesitation while delivering reliable results. These patient-friendly options—combined with the medical expertise of our infectious disease and gastrointestinal pathology teams and world-class turnaround times—make for a winning combination.

Keeping current with colorectal screening guidelines

The prevalence of digestive diseases has a significant impact in the United States, with more than 60 million Americans diagnosed each year. These conditions lead to more hospitalizations than any other disease state and represent the third-highest economic loss of all illnesses. Given the complexity of digestive diseases and the subtle presentation of symptoms, early and accurate detection is essential.1

When the American Cancer Society lowered its colorectal cancer screening age guideline from 50 to 45 for average-risk patients, an estimated 21 million people in the U.S. became newly eligible for screenings. Options include visual exams, such as a colonoscopy, and stool-based tests. Stool-based screenings are required more frequently than visual exams and should always be followed by a colonoscopy if results are abnormal. 

Learn more about Quest colorectal screening at

A comprehensive range of testing

Guidelines-based colorectal cancer testing

When colorectal cancer is caught in early stages, patients experience a 5-year survival rate exceeding 90%.2 And yet, more than 6 in 10 colorectal cancer patients receive their diagnosis after the cancer has already advanced. Once colorectal cancer spreads to distant organs, the 5-year survival rate drops to just 14%.2

These statistics emphasize the need for more screening, as well as the need to match diagnosed patients with highly targeted therapies. With noninvasive at-home kits and next-generation cancer genetic sequencing, Quest’s test menu supports providers in both objectives.

Colorectal cancer tests:

Comprehensive screening for celiac disease

The primary care community plays a pivotal role in identifying individuals at high risk for celiac disease (CD), performing serological testing as one of the first steps to diagnosis, and monitoring over time to detect associated conditions and nutritional deficiencies. Quest offers 3 serologic testing panels and genetic screenings so you can provide patients with fast, reliable insights.

Celiac disease tests:

Differential diagnosis of inflammatory bowel disease

Inflammatory bowel disease (IBD) involves chronic inflammation along the digestive tract at various sites, and includes Crohn disease (CD) and ulcerative colitis (UC). Because CD and UC manifest differently in digestive tissue and have different prognoses and treatments, differentiating between them is paramount. And yet, up to 15% of patients with IBD have cases that cannot be distinguished by clinical, radiographic, endoscopic, or histologic methods.3

Quest offers a range of stool and serum based assays that help rule out other possible conditions, confirm the presence of inflammation, and differentiate between inflammatory bowel syndrome (IBS) and IBD. Additionally, lab testing can help detect active versus remittant disease and predict relapse in patients with IBD.

Inflammatory bowel disease tests:

Specific diagnosis for symptoms of infectious diarrhea

When a patient presents with diarrhea, it’s important to determine whether the symptoms are caused by a bacteria, virus, or parasite in order to properly treat the infection. For some pathogens, an organism-specific diagnosis is required.4

Our broad infectious diarrhea testing menu can help you arrive at a differential diagnosis efficiently, so effective treatment can begin sooner.

The power of Quest


  1. GI Alliance. Digestive disease continues to rise among Americans. February 23, 2021. Accessed August 18, 2021.
  2. NCI Surveillance, Epidemiology, and End Results Program (SEER). Cancer stat facts: colorectal cancer. Survival statistics: 5-year relative survival. Accessed July 31, 2020.
  3. Savige J, Dimech W, Fritzler M, et al. Addendum to the International Consensus Statement on testing and reporting of antineutrophil cytoplasmic antibodies. Quality control guidelines, comments, and recommendations for testing in other autoimmune diseases. Am J Clin Pathol. 2003;120(3):312-318. doi:10.1309/WAEP-ADW0-K4LP-UHFN
  4. Shane L, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017;65(12):1963-1973. doi:10.1093/cid/cix959