Declarations
List of abbreviations: CC: Collagenous colitis; PPI: proton pump inhibitors; NSAIDs nonsteroidal anti-inflammatory drugs; CT: computed tomography; HE staining: hematoxylin and eosin stain;
Ethics approval and consent to participate: Not applicable
Consent for publication: Written informed consent was obtained from the patient.
Availability of data and materials: Not applicable
Competing interests: Not applicable
Funding: Not applicable
Author’s contributions: Not applicable
Acknowledgements: Not applicable