Home Stool Testing Matched Colonoscopy for Preventing Colon Cancer Deaths

CATEGORY: GUT & DIGESTIVE HEALTH

Can a kit used at the kitchen table do the job of a camera in a procedure room? A randomized trial of more than 57,000 Spanish adults aged 50 to 69 put the two screening offers side by side. After 10 years, 0.24% of the group offered an at-home stool test every two years had died of colorectal cancer, against 0.22% of the group offered a one-time colonoscopy.¹ By the standard the trial set in advance, that counts as no worse. More people also completed the stool test.

A Kit Every Two Years Against One Camera

Researchers invited adults at average risk of colorectal cancer, meaning no symptoms and no personal or family history, then split them at random between two screening offers. The first was a single colonoscopy, an exam in which a doctor inspects the entire large intestine with a thin, flexible camera while the patient is sedated. The second was a fecal immunochemical test, a small kit used at home that detects tiny traces of blood in the stool, an early warning sign of cancer, repeated every two years for up to five rounds. Anyone whose stool test came back positive was offered a colonoscopy to find the cause. Both groups were then followed for a full decade through health and death records, counting colorectal cancer cases and deaths.

55 Deaths Against 60, and a Bar Set in Advance

Over the 10 years, 55 people in the colonoscopy group (0.22%) and 60 people in the stool-test group (0.24%) died of colorectal cancer. That cleared the strict statistical bar the researchers had set before the trial began: a gap of less than 0.16 percentage points in colorectal cancer death risk at 10 years.¹ Colorectal cancers diagnosed over the decade came out much the same in both groups. Participation split the other way. Some 39.9% of the stool-test group completed screening, against 31.8% of the colonoscopy group. A colonoscopy usually means a day of bowel preparation, sedation and time away from work. The kit is finished at home in minutes and mailed back.

Invitations, Not Tests People Actually Take

This was a randomized trial, the strongest design for comparing two approaches, but what it compared was population-level screening invitations, and participation in both groups fell well short of public-health goals. The two tests are not rivals in practice either: a positive stool result leads to a colonoscopy, so they work as partners. The results apply to average-risk screening, not to people with symptoms or elevated risk. And a positive stool test is not a cancer diagnosis, since hemorrhoids and other benign conditions can leave blood in the stool too.

Wider evidence complicates the picture. A 2026 pooled analysis of nine randomized trials covering more than 830,000 people found that neither stool testing nor colonoscopy invitations clearly lowered colorectal cancer deaths against no screening over about a decade.² A larger Swedish trial of 278,000 adults found no drop in cancer diagnoses after about five years with either approach, and its death results are not yet reported.³

Key Takeaways

• An at-home stool test every two years matched a one-time colonoscopy invitation for preventing colorectal cancer deaths over 10 years, 0.24% against 0.22%, among more than 57,000 adults aged 50 to 69.¹
• Participation was higher with the kit: about 40% completed it, against about 32% for colonoscopy.
• A positive stool test is not a diagnosis, and it is followed up with a colonoscopy, so the two tests work together rather than in competition.

References

1. Castells A, Quintero E, Bujanda L, et al. Effect of invitation to colonoscopy versus faecal immunochemical test screening on colorectal cancer mortality (COLONPREV): a pragmatic, randomised, controlled, non-inferiority trial. The Lancet. 2025;405(10486):1231–1239. link
2. Kaneko M, Sakuraba A. Long-term effectiveness of endoscopic and stool-based colorectal cancer screening strategies: a systematic review and network meta-analysis. Therapeutic Advances in Gastroenterology. 2026;19:17562848261454186. link.
3. Westerberg M, Ludvigsson JF, Metcalfe C, et al. Colonoscopy and fecal immunochemical testing versus usual care in diagnostic colorectal cancer screening: the SCREESCO randomized controlled trial. Nature Medicine. 2026;32(4):1278–1285. link.