2023 Volume 56 Issue 2 Pages 63-68
The patient was a 67-year-old man who had been receiving treatment at our hospital for chronic kidney disease since 20XX-3. Because his general malaise, diarrhea, and anemia progressed from March 20XX, the patient was admitted to the hospital and underwent detailed examinations, but the cause could not be identified. In the same year, the patient began emergency dialysis due to hyperkalemia and metabolic acidosis. Although frequent blood transfusions and treatment with increased doses of erythropoiesis-stimulating agent preparations were performed, the patientʼs anemia showed minimal improvement, and his intractable diarrhea and high inflammatory response continued. A bone marrow biopsy was performed, and he was diagnosed with peripheral T-cell lymphoma. It was decided that the T-cell lymphoma would be followed by careful observation, and treatment for his anemia was continued. Collagenous colitis (CC) was diagnosed by lower gastrointestinal endoscopy performed for the purpose of detailed examination to identify the cause of the diarrhea. When the suspected drug, i.e., proton pump inhibitor (PPI) was discontinued, his symptoms improved. In this case, the chronic inflammation caused by CC was considered to be the main cause of his anemia. In hemodialysis patients, it is necessary to reduce the dose of H2 blockers from the viewpoint of renal dysfunction, and so the frequency of PPI use increases. Therefore, it is essential to recognize CC as a differential diagnosis for diarrhea in such patients.
