A 65-year-old client with acute diverticulitis reports severe left lower quadrant abdominal pain, fever of 101.2°F (38.4°C), and nausea. The client has constipation for 3 days and a history of diverticulosis. CT scan confirms mild inflammation. Which nursing intervention should be implemented first?

During acute diverticulitis, the inflamed diverticula need bowel rest to prevent further irritation and potential complications such as perforation or abscess formation. NPO status allows the bowel to rest while IV fluids maintain hydration and electrolyte balance. Acute diverticulitis is a condition where the diverticula, small pouches in the colon wall, become inflamed, primarily occurring in the sigmoid colon. Pathophysiologically, the diverticulum opening becomes obstructed by stool, leading to bacterial overgrowth, inflammation, and potential complications such as perforation, abscess formation, and peritonitis. The most important initial nursing intervention is maintaining NPO (nothing by mouth) status and administering intravenous fluids. This approach provides bowel rest, which is essential during the acute inflammatory phase. If the bowel continues to function through peristalsis and digestion, it can worsen inflammation in the affected diverticula and increase the risk of complications. NPO status eliminates mechanical and chemical stimulation of the bowel, allowing the inflammatory process to subside. IV fluid administration is equally important because NPO status can lead to dehydration and electrolyte imbalances. Patients with acute diverticulitis often experience nausea, vomiting, and fever, which further increase fluid loss. Maintaining adequate hydration supports tissue healing and prevents complications related to dehydration. This intervention aligns with the medical management approach for acute diverticulitis, which typically includes bowel rest, intravenous antibiotics, and supportive care. Nurses should monitor the patient's response to treatment, including pain levels, vital signs, and signs of complications such as increasing abdominal distension, worsening pain, and changes in bowel sounds.

Analysis of incorrect options:
- Option 2: Recommending increased fiber intake and ambulation during the acute phase can increase bowel stimulation and worsen inflammation.
- Option 3: Applying heat to the abdomen can increase blood flow to the inflamed area, worsening pain and swelling.
- Option 4: Enemas increase intraluminal pressure in the bowel, raising the risk of diverticular perforation, and are contraindicated during the acute phase.

Understanding the Clinical Scenario
The client is presenting with classic signs of acute diverticulitis: severe left lower quadrant pain, fever, nausea, and constipation. The CT scan confirms inflammation but is described as "mild," which aligns with a diagnosis of acute uncomplicated diverticulitis. In this acute inflammatory state, the colon is irritated and needs physiologic rest to prevent further complication such as perforation or peritonitis.

Prioritizing the First Intervention
The immediate priority is to reduce the workload on the inflamed bowel and manage systemic symptoms. The correct first step is to place the client on NPO status and administer IV fluids. This intervention serves two critical purposes. First, bowel rest through NPO status halts the introduction of food and fiber that would stimulate peristalsis and increase intraluminal pressure within the already inflamed diverticula. Second, IV fluids address the fluid deficit caused by fever and nausea, maintain hemodynamic stability, and correct dehydration, which is a foundational step before any other supportive measures.

Why the Other Options Are Incorrect or Delayed
- Encouraging increased fiber intake and ambulation is a management strategy for chronic diverticulosis to prevent future episodes, but it is contraindicated during an acute flare of diverticulitis. High-fiber foods would increase bowel wall stress and could exacerbate inflammation or trigger a perforation. This intervention is appropriate only after the acute inflammation has resolved.
- Applying heat to the abdomen is a comfort measure that can help relieve muscle spasms and pain. While it is a supportive nursing action, it does not address the underlying pathophysiologic process of inflammation and the risk of progression. Pain management is secondary to stabilizing the physiologic insult through bowel rest and hydration.
- Administering a Fleet enema to relieve constipation is strictly contraindicated in acute diverticulitis. An enema would forcefully increase intracolonic pressure, which can easily convert a contained, mild inflammation into a free perforation or abscess. The constipation is a symptom of the inflammation and will resolve as the acute process subsides with conservative management.

Connecting to Evidence-Based Practice
The foundational management of acute uncomplicated diverticulitis has shifted toward conservative, non-operative approaches, as highlighted in recent clinical research. A feasibility trial on a virtual care pathway for acute diverticulitis describes the conventional management of this condition as initial in-person assessment followed by supportive care, which inherently includes bowel rest and fluid resuscitation . The study’s premise relies on the fact that many patients with mild inflammation can be managed without immediate invasive procedures if the core principles of physiologic rest are applied first. Furthermore, a hospital-at-home study for acute complicated diverticulitis reinforces that even in more severe cases, the initial non-operative management strategy is built upon stabilizing the patient, which begins with ensuring hemodynamic stability and resting the gastrointestinal tract . The inclusion criteria for that study specifically required patients to be hemodynamically stable, a state that IV fluids help achieve and maintain. These sources support the clinical reasoning that before any advanced imaging, dietary changes, or invasive bowel regimens are considered, the first nursing action is to secure venous access, initiate fluid resuscitation, and place the patient on NPO status to rest the inflamed colon.