Douglas K. Rex, MD, FASGE




Douglas K. Rex, MD, FASGE, is Distinguished Professor of Medicine at Indiana University School of Medicine, Chancellor’s Professor at Indiana University Purdue University Indianapolis, and Director of Endoscopy at Indiana University Hospital in Indianapolis. He co-authored the colorectal cancer screening recommendations of the American College of Gastroenterology (ACG) and the U.S. Multi-Society Task Force on Colorectal Cancer. He also authored the recommendations on quality in colonoscopy of the U.S. Multi-Society Task Force on Colorectal Cancer and the ACG/American Society for Gastrointestinal Endoscopy (ASGE). He has authored more than 200 original research papers, 55 book chapters, 200 invited papers, 40 editorials, and 40 guideline papers. He is the current chair of the U.S. Multi-Society Task Force on Colorectal Cancer. He served in the ACG as Chairman of the Board of Governors and is a Past President of the ACG. He is a member of the Governing Board of ASGE and a recipient of the Rudolph V. Schindler Award from ASGE.



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  • Colon

    Considering Endoscopy in Iron Deficiency Anemia? Don’t Rely on Fecal Blood Testing to Decide

    Douglas K. Rex, MD, FASGE reviewing Lee MW, et al. Am J Gastroenterol 2020 Jan 10.

    Fecal blood testing is often used in clinical practice to triage patients into greater or lesser risk of diseases, such as GI tract cancer and inflammatory bowel disease. In this systematic review and meta-analysis of studies into iron deficiency anemia, ulcerative colitis, or acute diarrhea, researchers assessed the performance of fecal blood testing as a diagnostic tool.

  • Colon

    Berberine Reduces Metachronous Colorectal Adenomas in Randomized Trial

    Douglas K. Rex, MD, FASGE reviewing Chen YX, et al. Lancet Gastroenterol Hepatol 2020 Jan 8.

    Berberine is a Chinese herbal extract used to treat diarrhea and enteritis and is widely sold as a dietary supplement. There is some evidence it can block tumorigenesis. Approximately 1100 Chinese patients with a history of colorectal adenomas were randomized to receive berberine or placebo in this double-blind trial that evaluated the ability of berberine to reduce the risk of metachronous colorectal adenomas.

  • Colon

    Improving the Message of Mailed Outreach Improves CRC Screening Adherence

    Douglas K. Rex, MD, FASGE reviewing Bakr O, et al. Clin Transl Gastroenterol 2020 Jan.

    Mailed outreach, in which a fecal immunochemical test kit is sent directly to eligible patients, is increasingly recognized as a measure that improves colorectal cancer screening adherence. This study was a randomized trial that incorporated principles of behavioral economics and social psychology to make a more persuasive message in the mailed outreach.

  • Colon

    Updated Postpolypectomy Surveillance Recommendations of the Multi-Society Task Force

    Douglas K. Rex, MD, FASGE reviewing Gupta S, et al. Gastroenterology 2020 Feb 7.

    The U.S. Multi-Society Task Force on Colorectal Cancer has updated its recommendations for postpolypectomy surveillance for the first time since 2012. Among the changes, the recommended interval for postpolypectomy surveillance in patients with 1 or 2 tubular adenomas sized <10 mm is now 7 to 10 years versus 5 to 10 years, as previously recommended.

  • Colon

    Expanding Cold EMR to Large Laterally Spreading Lesions

    Douglas K. Rex, MD, FASGE reviewing Mangira D, et al. Gastrointest Endosc 2020 Jan 15.

    Serious adverse events, most often due to electrocautery, can occur when hot snare EMR is used to resect nonmalignant sessile polyps sized ≥20 mm. To determine the efficacy and safety of using cold snare piecemeal EMR to remove large polyps, researchers reviewed cases from 5 academic hospitals in which cold EMR was performed on 204 polyps ≥20 mm.

  • Colon

    High Definition Is Still the Only Way to Go

    Douglas K. Rex, MD, FASGE reviewing Tziatzios G, et al. Gastrointest Endosc 2020 Jan 15.

    Previous meta-analyses have suggested that the use of high-definition (HD) colonoscopy produces small gains in the adenoma detection rate. In an updated meta-analysis that identified 6 randomized controlled trials involving 4594 individuals with a mixture of indications, researchers further assessed the effect of HD colonoscopy on adenoma detection.

  • Colon

    Artificial Intelligence for the Other Half of Detection at Colonoscopy

    Douglas K. Rex, MD, FASGE reviewing Thakkar S, et al. Gastroenterology 2020 Jan 13.

    Thus far, artificial intelligence (AI) programs to improve detection have focused on recognition of lesions when they come into the endoscopic field of view. The current study is a description of an AI program that is one of a few to address assessment of the quality of the endoscopist’s mucosal exposure efforts.

  • Colon

    Cancer After Colonoscopy in UK Study Associated With, Well, Some Very Poor-Quality Colonoscopy

    Douglas K. Rex, MD, FASGE reviewing Anderson R, et al. Gastroenterology 2020 Jan 8.

    Much of the quality movement in colonoscopy has been directed to preventing interval cancer following colonoscopy. To determine the factors that cause this outcome, researchers reviewed cases of 107 interval cancers at a single medical center, involving 61,110 colonoscopies over an 11-year period with a 3-year interval cancer rate of 4.7%.

  • Colon

    End-Stage Renal Disease Still Risk Factor for Colonoscopy Complications

    Douglas K. Rex, MD, FASGE reviewing Yang SC, et al. J Gastroenterol Hepatol 2020 Jan 3.

    End-stage renal disease (ESRD) has been considered a risk factor for colonoscopy complications because of platelet dysfunction, in the case of bleeding, and perhaps tissue fragility, with regard to perforation. In a study involving 5302 patients with ESRD and the same number of matched controls, researchers assessed risk associated with postpolypectomy bleeding and polypectomy-related perforation.

  • Colon

    How Do We Get to 80% Screening?

    Douglas K. Rex, MD, FASGE reviewing Inadomi JM, et al. Clin Gastroenterol Hepatol 2019 Dec 27.

    The National Colorectal Cancer Roundtable set a goal of achieving 80% adherence to colorectal cancer screening in the U.S. by 2018. No individual state has achieved that level, and most states have adherence rates in the 60% to 70% range. This review examined the evidence regarding what measures are effective in increasing adherence.

  • Colon

    Small Left-Sided Polyps Seen During Colonoscope Insertion: Remove Them When You See Them

    Douglas K. Rex, MD, FASGE reviewing Teramoto A, et al. Gastrointest Endosc 2019 Dec 23.

    Experienced colonoscopists know that when a small polyp is encountered during insertion, it is best to remove it immediately, as identifying it during withdrawal is sometimes difficult. In this trial, patients were randomized to either removal of a left-sided lesion <1 cm in size during insertion or saving it for removal during withdrawal; researchers sought to determine whether there are clinical advantages to immediate removal of lesions during insertion.

  • Colon

    Observations on FIT-Fecal DNA Testing in Clinical Practice

    Douglas K. Rex, MD, FASGE reviewing Vakil N, et al. Gastrointest Endosc 2020 Jan 2.

    The FIT (fecal immunochemical test)-fecal DNA test is expensive, has a significant false-positive rate, and is dominated by both FIT and colonoscopy from a cost-effectiveness perspective. This study examined outcomes of FIT-fecal DNA testing conducted in one health care system to determine test effectiveness and patient compliance in a clinical setting.

  • Colon

    For Left-Sided Colon Lesions up to 25 mm and Right-Sided Colon Lesions up to 20 mm, Piecemeal EMR Is as Good as en Bloc Resection

    Douglas K. Rex, MD, FASGE reviewing Tate DJ, et al. Gastrointest Endosc 2019 Dec 27.

    Advanced endoscopists are often tempted to remove laterally spreading lesions (LSLs) up to 25 mm in size en bloc. In the current study, LSLs up to 25 mm in the left side of the colon and up to 20 mm in the right colon were considered eligible. Of 570 included lesions, 259 were removed by en bloc EMR and the remainder were removed piecemeal to compare long-term outcomes of size-matched LSLs.

  • Colon

    Brits Shake Up Postpolypectomy Surveillance

    Douglas K. Rex, MD, FASGE reviewing Rutter MD, et al. Gut 2019 Nov 27.

    Radical revisions have been made to British guidelines on postpolypectomy surveillance. Among the changes are new definitions for "high-risk group" and "premalignant" and a recommendation that patients without high-risk findings should return to routine fecal blood screening.

  • Colon

    Polygenic Risk Score Has Predictive Value for Early Onset Colorectal Cancer

    Douglas K. Rex, MD, FASGE reviewing Archambault AN, et al. Gastroenterology 2019 Dec 19.

    Everyone wants to understand the underlying drivers of the increase in early-onset colorectal cancer (CRC) and to have predictive risk scores that would allow tailored screening. In this case-control study involving multiple centers, 50,000 CRC cases, and 58,000 controls, a polygenic risk score based on 95 genetic variants was tested against CRC risk.

  • Colon

    Review and Meta-analysis Finds FIT CRC Sensitivity Lower in Stage I and T1

    Douglas K. Rex, MD, FASGE reviewing Niedermaier T, et al. Am J Gastroenterol 2019 Dec 10.

    Fecal immunochemical test (FIT) sensitivity for colorectal cancer is often cited at about 80%, using the 20 microgram Hgb/g feces cut-off. However, it is important to know the stage-specific performance because detection of early stages has greater value than detection of late stages. This systematic review and meta-analysis of 44 studies examines the stage-specific sensitivity of FITs.

  • Colon

    Not Asking Enough Questions: Low Rates of Recommending and Receiving Genetic Testing in U.S. in Those at Risk for Lynch Syndrome

    Douglas K. Rex, MD, FASGE reviewing Faust N, et al. Gastroenterology 2019 Dec 6.

    The National Health Interview Survey is conducted every 5 years and includes questions on genetic testing. In this study, responses from 2005, 2010, and 2015 regarding genetic testing discussion, recommendation, and completion were evaluated according to whether subjects had 0, 1, or ≥2 Lynch syndrome risk factors.

  • Colon

    Endoscopic Resection Effective for SSPs ≥10 mm in Meta-analysis; Cold EMR May Be Best

    Douglas K. Rex, MD, FASGE reviewing Chandrasekar VT, et al. Clin Gastroenterol Hepatol 2019 Nov 28.

    This systematic review and meta-analysis identified 911 patients with 1137 sessile serrated polyps ≥10 mm in 14 studies, in which resection was performed by hot EMR in 8 studies, hot EMR and a second technique in 2, cold EMR in 2, and standard snare resection in 1.

  • Colon

    New ASGE Guideline on Endoscopy and Management of ACPO and Colonic Volvulus

    Douglas K. Rex, MD, FASGE reviewing Naveed M, et al. Gastrointest Endosc 2019 Nov 29.

    The American Society for Gastrointestinal Endoscopy has released a set of recommendations on the management of volvulus and acute colonic pseudo-obstruction that covers such issues as when to use endoscopic treatment with a decompression tube, surgical management, and neostigmine therapy.

  • Colon

    Endocuff Vision Defeats Cap in Tandem Study

    Douglas K. Rex, MD, FASGE reviewing Rameshshanker R, et al. Gastrointest Endosc 2019 Dec 10.

    Recent controlled trials comparing Endocuff Vision to cap-assisted colonoscopy have had mixed results. This is the first randomized tandem study to compare the two devices.