Mercy Colorectal Surgeon Dr. Rebecca Brown and Rectal Cancer/Pulmonary Embolism Connection

News appeared nationally in February 2026 that actress and comedy icon Catherine O'Hara, 71, had died of a pulmonary embolism with rectal cancer believed to be the underlying cause. How is colorectal cancer related to pulmonary embolism, a sudden, life-threatening blockage in one of the pulmonary arteries in the lungs, typically caused by a blood clot traveling from the legs or other body parts. Rebecca Brown, M.D., a board certified colorectal surgeon with The Melissa L. Posner Institute for Digestive Health and Liver Disease at Mercy offers insights:

Reading the news of Catherine O’Hara’s passing—and the release of her death certificate—evokes a heavy mix of personal sadness and professional concern. While I (and the world) mourn the loss of a comedic icon (who among us hasn't shouted "fold it in!" in the kitchen?), those of us in the colorectal field see a sobering reminder of the quiet, invisible battle this disease represents.

Many are surprised to see "Pulmonary Embolism" listed alongside "Rectal Cancer" on a death certificate. Clinically, cancer creates a state of hypercoagulability. Essentially, the body’s chemistry changes, making the blood more prone to "thickening" and leading to increased risk of blood clot (Deep Vein Thrombosis) formation.

Typically, the "scariest" of these clots form in the large veins of the legs. If a piece of that clot breaks loose, it can travel directly to the lungs, blocking the vital vessels responsible for gas exchange. This prevents the body from shedding CO2 and absorbing oxygen—a transfer that is, quite literally, imperative to life.

The loss of Ms. O’Hara—joining the ranks of others we’ve lost too soon like Chadwick Boseman, Kirstie Alley and most recently James Van Der Beek—is a call to action for all of to ensure we are up to date on our colorectal cancer screening.  Colonoscopy remains the best tool we have for colorectal cancer screening (Gold Standard).  Screening should begin at age 45 (earlier if you have a family history of colorectal cancer or polyps). Unlike many other screenings, a colonoscopy doesn’t just find cancer; it prevents it. By removing precancerous polyps during the procedure, we stop the disease before it even starts.

I think it’s safe to say Catherine O’Hara would want us to take our health as seriously as she took her craft. So, when it comes to your colonoscopy and the dreaded colonoscopy prep: don’t overthink it, don’t delay it—just "fold it in".

- Rebecca Brown, M.D.

Dr. Rebecca Brown received her medical degree from University of New Mexico School of Medicine in 2012 and has expertise in treating colorectal cancer, diverticulitis, inflammatory bowel disease (e.g. Crohn’s Disease and Ulcerative Colitis), rectal prolapse, pelvic floor dysfunction, complex anorectal pathology, rectal bleeding and pain. She specializes in colorectal surgery and surgical oncology. She sees patients at Mercy Physicians at Frederick in Frederick, MD.