Fever and LLQ tenderness without peritonitis, abscess or fistula = uncomplicated diverticulitis, which is treated conservatively with antibiotics (oral in mild cases, NPO + IV fluids + IV antibiotics in more severe disease). Colonoscopy is avoided in the acute phase (perforation risk), percutaneous drainage is for an abscess on CT, and surgery is for generalized peritonitis or refractory disease. Antibiotics with observation is the only option that fits.