eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2022-06-06 10 6 173 175 10.12691/ajmcr-10-6-3 AJMCR20221063 article Shawn Philip shawn.philip316@gmail.com 1 Muhammad Farhan Ashraf 1 Mary Strader 2 Hala Abdelwahab 3 Asra Batool 3 Albany Medical Center, Department of Internal Medicine, Albany, NY. USA Albany Medical Center, Department of Gastroenterology, Albany, NY. USA Albany Medical Center, Department of Pathology, Albany, NY. USA Sevelamer is phosphate lowering oral agent used in chronic kidney disease (CKD) to decrease oral phosphate absorption. Sevelamer has been shown to cause crystalline induced colitis. This can manifest as abdominal pain or gastrointestinal bleeding. We present a case with chronic kidney disease and Moyamoya syndrome that presented with abdominal pain and anemia. Colonoscopy revealed a single circumferential cratered ulcer in the transverse colon. Pathology showed crystalline induced colitis. Sevelamer was discontinued and the patient`s symptoms improved. http://pubs.sciepub.com/ajmcr/10/6/3/ajmcr-10-6-3.pdf Sevelamer colitis ulcer