Symptoms of Diverticulitis
Adults over 40 with acute diverticulitis most commonly present with left lower quadrant abdominal pain and tenderness (70-97% of cases), accompanied by fever, with additional symptoms including abdominal distention, anorexia, constipation, nausea, diarrhea, and dysuria 1.
Primary Clinical Presentation
The symptom triad that should raise immediate suspicion consists of:
- Left lower quadrant pain - the hallmark symptom present in the vast majority of patients
- Abdominal tenderness on palpation, particularly localized to the left lower abdomen
- Fever - indicating inflammatory response
These three features appear in 70-97% of patients presenting with acute diverticulitis 1, 2.
Additional Common Symptoms
Beyond the classic triad, patients frequently report:
- Abdominal distention - from localized inflammation and ileus
- Altered bowel habits - either constipation or diarrhea
- Anorexia and nausea - reflecting systemic inflammatory response
- Dysuria - when inflammation involves the bladder wall 1
Important Clinical Caveats
Age and Location Variations
Right-sided diverticulitis presents differently and occurs more commonly in younger patients 2. When diverticulitis affects the right colon (which happens in approximately 10% of cases), patients may present with right lower quadrant pain that mimics appendicitis. This variant is more likely to be associated with abscesses and fistulas, and often leads to emergency surgical intervention due to diagnostic uncertainty 2.
Duration Matters for Risk Stratification
Symptom duration exceeding 5 days before clinical presentation predicts progression to complicated diverticulitis 3. This is a critical red flag that should lower your threshold for imaging and more aggressive management.
Signs of Complicated Disease
Clinicians must actively assess for features suggesting complicated diverticulitis (perforation, abscess, obstruction, or bleeding):
- Signs of peritonitis (rebound tenderness, guarding, rigidity)
- Hemodynamic instability
- Inability to tolerate oral intake
- Severe or worsening pain despite initial management
- Palpable mass suggesting abscess formation
Diagnostic Approach
While detailed history and physical examination establish the clinical suspicion, abdominal CT imaging should be used when diagnostic uncertainty remains, particularly at first presentation or when symptoms suggest alternative diagnoses 3. The moderate-certainty evidence shows CT has very high sensitivity and specificity for confirming diverticulitis and excluding mimics like colorectal cancer, gynecologic pathology, or inflammatory bowel disease 3.
Initial laboratory evaluation should include complete blood count (looking for leukocytosis), basic metabolic panel, urinalysis (to exclude urinary tract infection), and C-reactive protein (elevated in inflammatory states) 1.
What Symptoms Are NOT Typical
Importantly, most patients with diverticulosis (the presence of diverticula without inflammation) remain completely asymptomatic. Only 10-25% of people with diverticula ever develop symptomatic diverticulitis 4. The presence of diverticula on prior colonoscopy does not predict who will develop acute inflammation.