The advanced practice registered nurse (APRN) is assessing a patient who presents with fever, diarrhea, pelvic pain, and left lower quadrant pain. The patient reports the symptoms have been gradually getting worse. What is the most likely diagnosed based on these symptoms?

A. Acute pancreatitis is incorrect because it typically presents with severe epigastric pain that often radiates to the back, along with nausea and vomiting. The pain is not usually localized to the left lower quadrant, and diarrhea is not a primary feature. B. Acute appendicitis is incorrect because the classic presentation includes right lower quadrant pain (McBurney’s point), often beginning as periumbilical pain that later localizes to the RLQ. Left lower quadrant pain is not typical unless there is an anatomical variation. C. Acute biliary colic is incorrect because it presents with right upper quadrant pain, often after eating fatty foods, and may radiate to the right shoulder or back. It does not typically cause left lower quadrant or pelvic pain. D. Acute diverticulitis is correct because it commonly presents with left lower quadrant abdominal pain, fever, and changes in bowel habits such as diarrhea or constipation. The pain is often gradual in onset and progressively worsens, and may be associated with pelvic discomfort, especially when the sigmoid colon is involved.