What are the typical symptoms of uncomplicated left‑sided diverticulitis?

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Last updated: February 17, 2026View editorial policy

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Typical Symptoms of Uncomplicated Left-Sided Diverticulitis

Uncomplicated left-sided diverticulitis classically presents with left lower quadrant pain or tenderness, often accompanied by fever and leukocytosis, though this complete triad occurs in only approximately 25% of cases. 1

Core Clinical Presentation

Primary Symptom

  • Acute pain or tenderness in the left lower quadrant is the hallmark symptom, reflecting localized inflammation of sigmoid or descending colon diverticula 1

Associated Symptoms

  • Fever – present in the classic triad but not universal 1
  • Anorexia – loss of appetite commonly accompanies the acute inflammatory process 2
  • Nausea – frequently reported alongside abdominal discomfort 2, 3
  • Constipation – altered bowel habits are typical 2
  • Diarrhea – some patients experience loose stools rather than constipation 2
  • Dysuria – urinary symptoms can occur due to proximity of inflamed sigmoid colon to the bladder 2
  • Abdominal distention – may develop as inflammation progresses 2, 4

Laboratory Findings

  • Elevated white blood cell count (leukocytosis) – part of the classic triad but variable in presentation 1
  • Elevated C-reactive protein (CRP) – increased inflammatory markers support the diagnosis 1

Critical Diagnostic Caveat

Clinical diagnosis based on symptoms alone is unreliable, with misdiagnosis rates of 34-68%. 1, 5 The classic triad of left lower quadrant pain, fever, and leukocytosis is present in only 25% of patients with diverticulitis, making imaging essential for confirmation. 1, 5

High-Accuracy Clinical Decision Rule

When all three of the following criteria are present, the diagnosis of acute diverticulitis has 97% accuracy 1:

  1. Direct tenderness only in the left lower quadrant
  2. CRP >50 mg/L
  3. Absence of vomiting

However, this combination occurs in only 24% of patients with suspected diverticulitis. 1

Imaging Confirmation

CT abdomen and pelvis with IV contrast is the gold standard diagnostic test, with 98-99% sensitivity and specificity, and should be obtained in most cases to confirm uncomplicated disease and exclude complications. 1, 5, 3 CT findings in uncomplicated diverticulitis include diverticula, thickening of the bowel wall, and increased density of the pericolic fat, without abscess or perforation. 1

Common Pitfall

Do not rely on clinical examination alone to make treatment decisions—the poor diagnostic accuracy means that imaging is essential to distinguish uncomplicated diverticulitis from complicated disease, colonic malignancy, and other causes of left lower quadrant pain. 1, 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Diagnosis and management of acute diverticulitis.

American family physician, 2013

Research

Diverticulitis: A Review.

JAMA, 2025

Research

Diverticular Disease: Rapid Evidence Review.

American family physician, 2022

Guideline

Approach to Left Lower Quadrant Pain

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2026

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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