Adverse Effects of Clindamycin in Patients with Ulcerative Colitis

A nurse is preparing to administer clindamycin to a patient diagnosed with a serious bacterial infection. The patient has a history of ulcerative colitis and has experienced gastrointestinal side effects when taking antibiotics in the past. Prior to the administration, which of the following adverse effects should the nurse monitor for specifically associated with clindamycin use in this patient?