A 45-year-old man presents to the emergency department with a 2-day history of left lower quadrant abdominal pain, fever, and an increased white blood cell count. He reports a history of similar episodes in the past, which resolved with antibiotics. On physical examination, tenderness and guarding are noted in the left lower quadrant. Based on the patient's presentation, what is the most appropriate next step in managing this patient's condition?
Immediately prepare the patient for exploratory surgery.
Prescribe antispasmodic medication and discharge with follow-up.
Perform an immediate barium enema to confirm the diagnosis.
Administer broad-spectrum antibiotics and provide supportive care.