While undergoing a routine mammogram, Mrs. B, age 76 years and in good health, was found to have right axillary adenopathy. A core biopsy confirmed the diagnosis of follicular lymphoma and she was referred to an oncologist who recommended treatment with six cycles of bendamustine, mitoxantrone, and rituximab. She tolerated the treatment fairly well except for mild lower abdominal discomfort for three to four days following infusion of chemotherapy. Prior to her fifth cycle of therapy, she reported chills, vomiting, and watery diarrhea without fever. Mrs. B volunteered one day per week at a nursing home and she noted that a stomach virus had circulated among the residents. Her symptoms resolved five days after her initial episode occurred and she proceeded with her fifth cycle of therapy.