Diverticulitis Diagnosis
Diagnosis
Predisposing Factors
- Right-sided diverticula is predominant in Asian populations, while left-sided disease is more common in Western populations
- A diet that is low in fiber & high in fat & red meat
- Incidence increases with age
- The disease is rare in individuals <40 years old
- Disease frequency is similar in both genders
- Other factors which may predispose to diverticulitis are colonic motility disorders, colonic wall defects, ingestion of nonsteroidal anti-inflammatory drugs (NSAIDs) & ingestion of corticosteroids
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 & pelvic exams
- Abdominal findings:
- Direct & rebound tenderness over the involved area is noted in cases of localized peritonitis
- Generalized tenderness, involuntary guarding & decreased or absent bowel sounds are seen in generalized peritonitis
- A mass is occasionally palpated at the site of inflammation & may be apparent on abdominal palpation, rectal or pelvic exam
- Abdomen may be distended & tympanic on percussion
- A rectal exam may help elicit tenderness, establish stool color & check for gastrointestinal bleeding
Laboratory Tests
- Complete blood count (CBC)
- Leukocytosis with or without a left shift indicates infection
- Immunocompromised & elderly patients may have normal results
- Liver function tests (LFTs), lipase, amylase
- May help establish other causes of abdominal pain
- Blood cultures
- Perform prior to giving empiric antibiotic therapy
- Urinalysis & urine cultures
- Demonstrate urinary tract infection (UTI), which is most likely due to a colovesicular fistula
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
Abdominal Computed Tomography (CT) Scan
- There is an increasing trend toward using the CT scan as the imaging test of choice for the evaluation of acute diverticulitis
- Sensitivity is reported at 79-99% with specificity at 72%
- Criteria for diagnosis of diverticulitis include the following:
- Colonic wall thickening
- Pericolic fat infiltration
- Pericolic or distant abscesses
- Extraluminal air
- Able to determine disease extent ie presence of abscesses, thus facilitating the decision of administering medical vs 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
- Not useful in differentiating cancer from diverticulitis
- Able to detect abscesses & 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 & 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 & 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
- Criteria for the diagnosis of diverticulitis include wall thickening, abscess & rigid hyperechogenicity of the colon
- The test is valuable in women of childbearing age who present with left lower abdominal quadrant pain & fever
- More sensitive than computed tomography (CT) or contrast enema in detecting gynecologic abnormalities eg ectopic pregnancy & pelvic inflammatory disease (PID)
Abdominal X-ray
- Provides limited information except in cases where perforation or obstruction are suspected
- Plain & upright films may show ileus, free air (pneumoperitoneum) or obstruction
Evaluation
The management of diverticulitis depends on the clinical presentation, severity of inflammation, location of the lesion & presence of concomitant diseases
Uncomplicated Diverticulitis
- Refers to diverticulitis without associated abscess, obstruction, fistula, perforation, or peritonitis
Complicated Diverticulitis
- Refers to diverticulitis with complications including abscess, obstruction, fistula, perforation, stricture, or peritonitis
- Divided into stages by the Hinchey classification