Objective:

To investigate whether chronic constipation and diarrhoea are temporally linked to colorectal cancer (CRC) diagnosis.

Approach:

• Study Design: Retrospective case–control study using real-world data from the German Disease Analyser database.
• Participants: 10,941 patients with CRC and 54,705 matched controls without cancer were included after 1:5 propensity score matching.
• Data Evaluation: Documentation of constipation and diarrhoea was evaluated in six time intervals up to 5 years before CRC diagnosis.
• Statistical Analysis: Multivariable conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for CRC risk.

Key Findings:

• Constipation was significantly more frequent in patients with CRC within 6 months prior to diagnosis (OR 3.23; 95% CI 2.85 to 3.66).
• Diarrhoea also showed a significant association within 6 months prior to diagnosis, with stronger associations for more frequent diagnoses.
• No associations were identified beyond 1 year before diagnosis.

Interpretation:

Constipation and diarrhoea were associated with CRC diagnosis only in the immediate months before diagnosis.

Limitations:

• The study relies on real-world data, which may have inherent biases.
• The retrospective design limits the ability to establish causation.

Conclusion:

Constipation and diarrhoea may serve as indicators for early CRC, highlighting the need for timely diagnostic evaluation.