From Gut to Lungs: The Hidden Respiratory Impacts of IBD: A Systematic Review of the Literature.

Pulmonary complications are an important yet underappreciated aspect of inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC). These conditions often manifest with extraintestinal symptoms that can significantly influence the clinical trajectory of the disease. Pulmonary involvement in IBD can range from mild symptoms, such as a persistent cough, to severe conditions, including interstitial lung disease or pulmonary embolism. This systematic review aims to assess the prevalence, clinical presentations, and implications of pulmonary involvement in IBD patients. A comprehensive literature search was conducted using PubMed database up to the 1st of May 2024. Inclusion criteria focused on studies involving adult IBD patients with documented pulmonary symptoms, evaluated through clinical, radiological, and histopathological approaches. Of the 463 studies identified, 27 met the inclusion criteria, consisting of 36,264 patients. Pulmonary manifestations were classified into airway diseases and parenchymal involvement. Airway diseases, including bronchiectasis and chronic bronchitis, were the most common, followed by parenchymal conditions such as organizing pneumonia and interstitial lung disease (ILD). Smoking was identified as a significant risk factor for pulmonary involvement. Pulmonary involvement in IBD is diverse and often underdiagnosed. Early recognition and management are crucial to improving patient outcomes.