Exploring the relationship between colorectal polyps and pulmonary nodules based on the theory of the lung and the large intestine being internally and externally connected.

Objective: To explore the relationship between colorectal polyps and pulmonary nodules from the perspective of the lung and the large intestine being internally and externally connected, aiming to provide a theoretical basis for clinical diagnosis and treatment.

Methods: We retrospectively analyzed the data of patients who underwent electronic colonoscopy and were found to have colorectal polyps at the Gastrointestinal Endoscopy Center of Dongfang Hospital, Beijing University of Chinese Medicine, from January 1, 2017, to December 31, 2023. We also reviewed their lung CT results and used statistical software to analyze the recurrence, location, size, and pathology of colorectal polyps in relation to the presence, number, and size of pulmonary nodules.

Results: Both colorectal polyps and pulmonary nodules are more common in elderly males. Patients with recurrent colorectal polyps are more likely to have pulmonary nodules, which tend to be located in the left colon and are more likely to be adenomatous in nature; those without pulmonary nodules show no clear pattern in polyp distribution, with a tendency towards inflammatory and hyperplastic pathology; the data from this study suggests that the proportion of lung nodules larger than 0.5 cm in the recurrent group is higher than in the non-recurrent group, and the proportion of colorectal polyps larger than 1 cm in the recurrent group is also higher than in the non-recurrent group.

Conclusion: There is a certain connection between the pathogenesis and treatment of colorectal polyps and pulmonary nodules. Cold, phlegm, dampness, blood stasis, and toxic coagulation are common pathogenic factors of the two diseases. Patients with larger colorectal polyps should be advised to undergo regular colonoscopy. Patients with recurrent polyps or those with left colon necrosis or cancer indicated by colonoscopy should be advised to complete lung related examinations to rule out the possibility of pulmonary nodules.