What are the symptoms and treatment options for diverticulitis?

Symptoms and Treatment of Diverticulitis

The primary symptoms of diverticulitis include acute or subacute abdominal pain typically located in the left lower quadrant, fever, change in bowel habits, nausea (though vomiting is less common), and elevated inflammatory markers such as white blood cell count and C-reactive protein. 1

Clinical Presentation

• Abdominal pain in the left lower quadrant is the most common presenting symptom 1
• Fever is a common accompanying sign 1, 2
• Change in bowel habits (constipation or diarrhea) may occur 3, 2
• Nausea is common, but vomiting is less frequent 4, 3
• Abdominal tenderness on examination, typically localized to the left lower quadrant 1, 2
• Laboratory findings often include leukocytosis and elevated C-reactive protein (CRP) 1, 2

Diagnostic Approach

• CT scan of the abdomen and pelvis with oral and intravenous contrast is the gold standard for diagnosis (sensitivity/specificity 95%) 1, 5
• Abdominal ultrasonography is an alternative that avoids contrast and radiation exposure, but is operator-dependent 1
• MRI is very sensitive but less specific than CT and generally not used in acute settings 1
• Clinical suspicion alone is correct in only 40-65% of patients, highlighting the importance of imaging 1

Classification of Diverticulitis

Uncomplicated Diverticulitis

• Involves thickening of the colon wall and peri-colonic inflammatory changes 1
• Infection limited to the colon without extension to the peritoneum 1

Complicated Diverticulitis

• Presence of abscess, peritonitis, obstruction, stricture, and/or fistula 1
• Only about 12% of patients present with complicated disease 1, 5
• Most common complication is phlegmon or abscess, followed by peritonitis, obstruction, stricture, and fistula 1

Treatment Options

For Uncomplicated Diverticulitis

• Conservative management without antibiotics is recommended for most patients with uncomplicated diverticulitis 1, 5
• Pain management primarily with acetaminophen 6, 5
• Clear liquid diet during the acute phase to reduce mechanical irritation 6, 2
• Advance diet as symptoms improve 6, 7
• Selective use of antibiotics for:
  • Patients with comorbidities or frailty 6, 5
  • Immunocompromised patients 1, 5
  • Patients older than 80 years 5, 7
  • Pregnant patients 5, 2
  • Those with persistent fever, increasing leukocytosis, or systemic symptoms 1, 5

For Complicated Diverticulitis

• Intravenous antibiotics (ceftriaxone plus metronidazole or piperacillin-tazobactam) 1, 5
• Percutaneous drainage for abscesses ≥ 3-4 cm 1, 3
• Surgical intervention for:
  • Failed percutaneous drainage 1, 7
  • Generalized peritonitis 1, 5
  • Fistula formation 1, 5
  • Obstruction 1

Antibiotic Options When Indicated

• Oral: amoxicillin/clavulanic acid or cefalexin with metronidazole 5, 8
• Intravenous: ceftriaxone plus metronidazole, ampicillin/sulbactam, or piperacillin-tazobactam 1, 5

Follow-up Care

• Colonoscopy is recommended 6-8 weeks after resolution of symptoms for:
  • Patients with complicated diverticulitis 1, 7
  • First episode of uncomplicated diverticulitis 1, 3
  • Can be deferred if high-quality colonoscopy was performed within the past year 1, 7

Long-term Management

• Approximately 45% of patients report periodic abdominal pain at 1-year follow-up 6, 7
• For persistent pain after acute episode resolves, low to modest doses of tricyclic antidepressants may help with visceral hypersensitivity 6, 4
• Preventive measures include:
  • High-fiber diet or fiber supplementation (though may cause bloating in some patients) 4, 7
  • Regular exercise 3, 7
  • Smoking cessation 3, 7
  • Weight loss for those with BMI ≥ 30 kg/m² 3, 7

Common Pitfalls and Caveats

• Malignancy can be misdiagnosed as diverticulitis, highlighting the importance of follow-up colonoscopy 1, 3
• Antibiotics do not prevent complications or recurrences in mild, uncomplicated diverticulitis 3, 2
• Complicated diverticulitis most often occurs with the first presentation rather than with recurrences 4, 7
• Chronic gastrointestinal symptoms, including abdominal distension, do not always improve with surgery 4, 7
• Smoldering diverticulitis (continued pain and inflammation on CT) affects approximately 5% of patients 1, 4