Diverticulitis Diagnosis
History
- 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
Imaging
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
Evaluation
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