Increased Risk of CRC in Patients With Slow-Transit Constipation

Slow-transit constipation (STC) is reported to occur in 15-30% of people in the U.S. The most widely accepted definition of STC is two or fewer bowel movements per week or straining at stool more than 25% of the time. Research continues to point to STC as a risk factor for colorectal cancer (CRC).

A study published in 2020 that looked at 2,165 patients (median age 54 years), found that the cumulative probability of CRC was 0.2% 5 years after STC diagnosis and 0.4% 10 years after STC diagnosis. This was not significantly different (p=0.575) than among those without STC diagnosis. However, this may be due to the small number of patients (5) who were diagnosed with CRC.

Although the authors of the 2020 study did not find a significant difference among those with and without STC diagnosis, it is well established that STC increases CRC risk. Gurérin et al. in their 2014 study of over 100,000 patients identified a statistically significant risk of CRC among those with STC:

• 56% higher for CRC
• 260% higher for benign neoplasm
• 256% higher for benign neoplasm in colon
• 262% higher for anal and rectal polyps

Current management options for STC range from dietary counseling, pharmacological therapy, and surgery. 

While the etiology of STC remains unclear, there is increasing evidence that it is caused by an imbalance in the gut microbiome. Zhang et al. in their 2021 review published in Gastroenterology Report found that gut microbiota may play a major role in modulating colonic motility, secretion, and absorption. However, there is still much research needed to understand how the gut microbiome modulates movement of fecal matter through the small intestine and colon.

Conversations about the role of the gut microbiome in CRC development were a part of the Early-Age Onset Colorectal Cancer Summit held by the Colon Cancer Foundation in May 2022.

Gargi Patel is a Colon Cancer Prevention Intern with the Colon Cancer Foundation.