A 47-year-old man was referred to our hospital with an abnormal shadow on a chest X-ray. He had a history of untreated chronic sinusitis and suspected ulcerative colitis (UC). Chest CT revealed a diffuse centrilobular granular shadow, while laboratory tests demonstrated an increased proportion of neutrophils; however, no microorganisms were detected in bronchoalveolar lavage fluid. Therefore, sinobronchial syndrome or small airway disease associated with UC was diagnosed, and the patient was treated with long-term erythromycin therapy. Small airway disease associated with UC is usually treated with steroids. Our experience shows that airway involvement in patients with inflammatory bowel disease can be treated with macrolides.