Treatment Guideline Chart
Diverticulitis is the inflammation of the diverticulum which is a herniation of the mucosa and submucosa of the colonic wall that may fill with fecal material or undigested food particles. 
Abdominal pain is usually localized, abrupt, steady and may worsen over time.
Other signs and symptoms are fever, anorexia, nausea without vomiting, and altered bowel movements, commonly constipation but may also present with diarrhea or tenesmus.

Diverticulitis Diagnosis


  • A thorough clinical history must be obtained to help rule out other causes of abdominal pain

Physical Examination

  • A complete directed physical exam must be conducted including abdominal, rectal and pelvic exams
  • Abdominal findings:
    • Abdomen may be distended and tympanic on percussion 
    • Generalized tenderness, involuntary guarding and decreased or absent bowel sounds are seen in generalized peritonitis
    • Direct and rebound tenderness over the involved area is noted in cases of localized peritonitis
    • A mass is occasionally palpated at the site of inflammation and may be apparent on abdominal palpation, rectal or pelvic exam
  • A rectal exam may help elicit tenderness, establish stool color and check for gastrointestinal bleeding


If the clinical picture is clear, some experts suggest that a diagnosis of diverticulitis can be made on the basis of clinical criteria alone

  • Selective imaging is recommended in patients with a previous history of acute diverticulitis, absence of vomiting, pain localized to the left lower quadrant and/or a C-reactive protein (CRP) level of >50 mg/L 

Abdominal Computed Tomography (CT) Scan 

  • The imaging test of choice for the evaluation of acute diverticulitis
    • Sensitivity is reported at 95% with specificity at 96%
  • Able to determine disease extent ie presence of abscesses, thus facilitating the decision of administering medical versus surgical therapy
  • May be employed in performing percutaneous drainage of abscesses
  • Able to show extracolonic diseases which may present with symptoms similar to those of diverticulitis eg tubo-ovarian abscess, aortic leakage
  • Criteria for diagnosis of diverticulitis include the following:
    • Colonic wall thickening
    • Pericolic fat infiltration
    • Pericolic or distant abscesses
    • Extraluminal air
    • Presence of intra-abdominal free fluid
  • Not useful in differentiating cancer from diverticulitis

Contrast Enema  

  • Able to detect abscesses and other colonic diseases eg ischemic colitis, inflammatory bowel disease (IBD) that may present in a similar manner
    • Not an imaging test of choice during an acute episode of abdominal pain
  • May underestimate the severity of the disease because it cannot demonstrate the extramural nature of diverticulitis
  • Cost of the test is low and test is available in most centers
  • Use of water-soluble contrast media is advisable
    • Barium contrast is generally not recommended because of the risk of colonic perforation and subsequent peritonitis
  • Criteria for diagnosis of diverticulitis include the following:
    • Presence of diverticula, intramural mass, mass effect or sinus tract
    • Extravasation of contrast suggests perforation 

Transabdominal Ultrasound  

  • Safe noninvasive test but is examiner-dependent
    • Avoids radiation but less accurate in detecting abscess
  • An alternative to CT scan when it is not available or is contraindicated 
  • The test is valuable in women of childbearing age who present with left lower abdominal quadrant pain and fever
    • More sensitive than CT or contrast enema in detecting gynecologic abnormalities eg ectopic pregnancy and pelvic inflammatory disease (PID)
  • Criteria for the diagnosis of diverticulitis include wall thickening, abscess and rigid hyperechogenicity of the colon 

Magnetic Resonance Imaging (MRI)

  • Has high sensitivity and specificity but time-consuming 
  • An alternative to CT scan when it is not available or is contraindicated 
  • May be used when ultrasound is found to be inconclusive in pregnant women
  • May be more useful than CT in differentiating carcinoma from diverticulitis

Abdominal X-ray  

  • Provides limited information except in cases where perforation or obstruction are suspected
  • Plain and upright films may show ileus, free air (pneumoperitoneum) or obstruction

Laboratory Tests

Complete Blood Count (CBC)

  • Leukocytosis with or without a left shift indicates infection
  • Immunocompromised and elderly patients may have normal results

Liver Function Tests (LFTs), Lipase, Amylase

  • May help establish other causes of abdominal pain

C-reactive Protein (CRP)

  • Correlates with disease severity and recurrence

Blood Cultures

  • Perform prior to giving empiric antibiotic therapy

Urinalysis and Urine Cultures

  • Demonstrate urinary tract infection (UTI), which is most likely due to a colovesicular fistula


The management of diverticulitis depends on the clinical presentation, severity of inflammation, location of the lesion and presence of concomitant diseases

Uncomplicated Diverticulitis

Acute Uncomplicated Diverticulitis 

  • Refers to diverticulitis without associated abscess, obstruction, fistula, perforation, or peritonitis

Chronic Uncomplicated Diverticulitis 

  • Refers to an incomplete resolution of an acute diverticulitis with absence of luminal stenosis

Complicated Diverticulitis

  • Findings suggestive of complicated diverticulitis:
    • Severe, generalized abdominal pain with abdominal rigidity and guarding may be due to peritonitis
    • Abdominal mass on palpation or peri-rectal fullness on rectal exam with intra-abdominal abscess
    • Abdominal distention with colicky pain, constipation or vomiting in cases of intestinal obstruction
    • Purulent or fecaloid vaginal discharge in patients with colovaginal fistulas
    • Fecaluria or pneumaturia in patients with colovesicular fistulas
    • Back or lower extremity pain in cases of retroperitoneal gut perforation

Acute Complicated Diverticulitis

  • Refers to diverticulitis with complications including abscess, obstruction, fistula, perforation, stricture, or peritonitis
  • Divided into stages by the Hinchey classification
    • Hinchey I: Pericolic abscess
    • Hinchey II: Intra-abdominal/retroperitoneal/pelvic abscess
    • Hinchey III: Purulent peritonitis
    • Hinchey IV: Fecal peritonitis

 Chronic Complicated Diverticulitis

  • Includes stenotic disease that can lead to fistula formation and acute bowel obstruction


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