TOPLINE:

In a prospective cohort study, nearly half of the survivors of colorectal cancer reported bowel-related symptoms at 6 months, whereas more than one third still had symptoms at 5 years. Higher dietary fiber intake was associated with a lower prevalence of moderate-to-severe diarrhea.

METHODOLOGY:

• Survivors of colorectal cancer commonly experience bowel symptoms (diarrhea, urgency, constipation, or bloating), with established risk factors including rectal tumors, radiotherapy, and low anterior resection. However, longitudinal data on these symptoms, and the role of diet, are limited.
• Researchers analyzed data from 1751 survivors of colorectal cancer (median age at diagnosis, 66 years) who were part of the longitudinal COLON study. All patients were surgically treated for stages I-IV disease and followed up for ≤ 5 years.
• Patient‑reported bowel symptoms were recorded at 6 months, 2 years, and 5 years after diagnosis via a questionnaire, and habitual dietary fiber intake was assessed at the same time points using a 204-item food frequency questionnaire.
• Multivariable logistic regression was used to analyze associations between fiber intake and the prevalence of bowel symptoms, with adjustment for factors such as age, current stoma, physical activity levels, and smoking status.

TAKEAWAY:

• Overall, the prevalence of bowel‑related symptoms was 46.7% (817/1751) at 6 months, 40.6% (614/1511) at 2 years, and 35.7% (290/812) at 5 years after diagnosis.
• Higher fiber intake (per 10 g/d increment) was associated with a significantly lower prevalence of moderate-to-severe diarrhea at 6 months (odds ratio [OR], 0.44) and 2 years (OR, 0.53), but it was not associated with constipation. Fiber might be protective against diarrhea due to its effects on gut health, including the microbiome, the authors noted, but reverse causation cannot be ruled out.
• In analyses of individual symptoms, higher fiber intake was associated with lower odds of diarrhea at 2 years (OR, 0.48) and 5 years (OR, 0.48), lower odds of mucus in stools at 6 months and 2 years, and higher odds of flatulence or bloating at 6 months (OR, 1.57). Diarrhea was associated with lower health-related quality-of-life scores at all time points, with the lowest scores observed 5 years after diagnosis (regression coefficient β, -9.6; 95% CI, -14.0 to -5.2).
• Persistent bowel symptoms among survivors of colorectal cancer have been primarily attributed to low anterior resection. In this study, symptoms were more prevalent among patients who received low anterior rection vs hemicolectomy. But lasting symptoms were most common among patients who received radiotherapy (53.8% of patients at 2 years and 51.1% at 5 years).

IN PRACTICE:

“Higher intake of dietary fiber was associated with a lower prevalence of diarrhea, which implies the potential role of nutritional counseling in management of bowel-related symptoms” the authors wrote. “Our findings provide an evidence base for investigating nutritional strategies, including increasing dietary fiber intake, to target bowel-related symptoms in CRC [colorectal cancer] survivors.”

SOURCE:

The study, led by Niels Klaassen-Dekker, MSc, Wageningen University & Research in Wageningen, Netherlands, was published online in JAMA Network Open.

LIMITATIONS:

The limitations of the study were its observational design and lack of data on treatment modalities for managing bowel-related symptoms. Additionally, baseline symptom data at diagnosis and a matched comparison group without cancer were not available to assess whether symptom prevalence was increased compared to the general population.

DISCLOSURES:

The study received financial support from the VLAG Graduate School of Wageningen University & Research. One author reported receiving grants from the World Cancer Research Fund. Another author disclosed receiving grants from Danone Global Research & Innovation Center outside the submitted work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.