Achilles tendinitis as a rare extraintestinal manifestation of ulcerative colitis.

Patients with inflammatory bowel disease often have extraintestinal manifestations (EIMs) involving almost all organ systems, but little has been reported on Achilles tendinitis. Herein, we present a unique case of Achilles tendinitis, which manifested shortly after initiation of mesalazine therapy for ulcerative colitis. A 26-year-old Japanese woman with bloody diarrhea and abdominal cramps lasting for 7 days was referred to our hospital.