Question

During an evaluation at an urgent care clinic, a 48-year-old man describes a two-day history of worsening left lower quadrant abdominal pain. The pain is constant and described as an aching sensation. He reports having a mild decrease in appetite but denies nausea, vomiting, melena, or hematochezia. His medical history is unremarkable, and he takes no daily medications. Vital signs are temperature $37.3^\circ\text{C}$ ($99.1^\circ\text{F}$), heart rate $82/\text{min}$, blood pressure $128/82\text{ mmHg}$, and respiratory rate $14/\text{min}$. Physical examination reveals a non-distended abdomen with focal tenderness to deep palpation in the left lower quadrant. There is no rebound tenderness, guarding, or rigidity. Laboratory studies show a leukocyte count of $10,200/\text{mm}^3$ with a normal differential. A computed tomography scan of the abdomen and pelvis with intravenous contrast demonstrates scattered diverticula in the sigmoid colon, localized colonic wall thickening, and mild pericolonic fat stranding. There is no evidence of an abscess, fistula, stricture, or free intraperitoneal air. The patient easily tolerates drinking a glass of water during the evaluation. Which of the following is the most appropriate next step in management?