Diverticulitis

Aka: Diverticulitis

1. See Also
   1. Diverticulosis
2. Pathophysiology
   1. Complicates 5% of Diverticulosis
   2. Distribution
      1. Most often affects sigmoid colon
      2. Right Diverticular Disease in age <60 and asians
   3. Inflammation of colonic Diverticula
      1. Impacted with fecal material (fecalith)
      2. Colon Perforation
         1. Microperforation (Simple Diverticulitis)
            1. Peridiverticulitis with localized phlegmon
            2. Infection walled off by pericolic fat
         2. Macroperforation (Complicated Diverticulitis)
            1. Pericolic abscess or
            2. Free perforation with generalized peritonitis
            3. Fistulas may form between adjacent structures
3. Symptoms
   1. Mild anorexia
   2. Nausea or Vomiting
   3. Chills
   4. Diarrhea or obstipation
   5. Abdominal Pain: Acute constant pain
      1. Initial: Hypogastric pain
      2. Later: Left Lower Quadrant Abdominal Pain (>92%)
4. Signs
   1. Fever
   2. Tenderness over left lower quadrant
   3. Guarding and rebound tenderness may be present
5. Labs
   1. Complete Blood Count
      1. Leukocytosis (>68% of cases)
   2. Urinalysis
      1. Dysuria and urinary frequency may occur
6. Differential Diagnosis
   1. See Left Lower Quadrant Abdominal Pain
7. Imaging
   1. Abdominal CT with oral contrast (preferred)
      1. Best test to confirm Diverticulitis
         1. Test Sensitivity: Approaches 100% (sigmoid involvement)
         2. Test Specificity: Approaches 100% (sigmoid involvement)
      2. Best test to identify complications (perforation)
      3. Findings suggestive of Diverticulitis
         1. Pericolonic fat infiltration or stranding
         2. Fascial thickening
         3. Muscle hypertrophy (Test Specificity 98% in Diverticulitis)
         4. Arrowhead sign
            1. Localized bowel wall thickening
            2. Bowel lumen resembles arrow shape at diverticulum
      4. References
         1. Kaiser (2005) Am J Gastroenterol 100(4): 910-7
   2. Abdominal flat and upright Abdomen
      1. Observe for abdominal free air
      2. Small Bowel Obstruction
   3. Abdominal MRI
      1. Not routinely used in practice for this indication (high cost, long scan times)
      2. MRI findings are similar to CT, but with better resolution of soft tissue
         1. Buckley (2007) Eur Radiol 17(1): 221-7
   4. Abdominal Ultrasound
      1. Not routinely used in practice for this indication
      2. Reliable for diagnosis of sigmoid Diverticulitis but variable efficacy due to technique, body habitus and acute pain
         1. Schwerk (1992) Dis Colon Rectum 35(11): 1077-84
      3. Unlike CT Abdomen, does not evaluate alternative diagnoses for Abdominal Pain
      4. Consider in women for evaluating additional Pelvic Pain causes (including pregnancy-related)
   5. Avoid Colonoscopy in acute disease
      1. Risk of worsening perforation
   6. Avoid Barium Enema in acute disease
      1. Risk of extravasation if perforation
8. Management: General Measures
   1. Clear Liquid Diet (NPO in severe disease)
   2. Low fiber diet in acute phase
   3. Avoid Narcotics (increases intracolonic pressure)
      1. Except Meperidine (decreases intraluminal pressure)
   4. Anticipate improvement within 48-72 hours
9. Management: Outpatient Mangement of mild disease
   1. Indications for outpatient management
      1. Uncomplicated Diverticulitis
      2. Stable clinically
      3. Tolerating oral fluids
   2. Antibiotic regimen
      1. Primary protocol (requires 2 agents for 7-10 days)
         1. Ciprofloxacin 500 mg PO bid or Septra DS PO bid and
         2. Metronidazole (Flagyl) 500 mg PO q6 hours
      2. Alternative protocol
         1. Augmentin 500 mg PO tid for 7-10 days
10. Management: Inpatient
    1. Indications for hospitalization
       1. Age >85 years
       2. Significant inflammation
       3. Unable to take oral fluids
    2. General measures
       1. Nothing by mouth initially
    3. Antibiotic regimen for moderate disease
       1. Primary agents
          1. Unasyn 3 g IV q6 hours
          2. Zosyn 3.375 g IV q6 hours
          3. Timentin 3.1 g IV q6 hours
       2. Alternative agents
          1. Cefoxitin 2 g IV q8 hours
          2. Cefotetan 2 g IV q12 hours
          3. Ciprofloxacin 400 mg IV q12h with Flagyl 500 IV q6h
    4. Antibiotic regimen for severe disease (e.g. ICU)
       1. Primary agents
          1. Imipenem 500 mg IV q6 hours or
          2. Merepenem 1 g IV q8 hours
       2. Alternative agents
          1. Trovafloxacin 300 mg IV day 1, then 200 mg IV qd or
          2. Three agent protocol 1
             1. Ampicillin 2 g IV q6 hours and
             2. Metronidazole 500 mg IV q6 hours and
             3. Aminoglycoside (requires monitoring of levels)
                1. Gentamicin or
                2. Tobramycin or
                3. Amikacin
          3. Three agent protocol 2
             1. Ampicillin 2 g IV q6 hours and
             2. Metronidazole 500 mg IV q6 hours
             3. Ciprofloxacin 400 mg IV q12 hours
11. Course
    1. Improves on antibiotics within 48 to 72 hours
12. Follow-up
    1. Colonoscopy 6 weeks after Diverticulitis episode
       1. Define extent of Diverticulosis
       2. Evaluate for Colon Cancer
       3. Barium Enema may be used as alternative option
    2. Surgical indications
       1. Recurrent Diverticulitis (more than 1 episode)
13. Complications
    1. Colonic perforation
    2. Colonic abscess
    3. Generalized peritonitis
    4. Colonic fistula
14. Prevention
    1. High fiber diet (except in acute phase - see above)
    2. Maintain adequate hydration
15. Prognosis
    1. After first episode, recurs in 20-30% of cases
    2. After second episode, recurs in 50% of cases
16. References
    1. Gilbert (2002) Sanford Guide to Antimicrobials, p. 14
    2. Simmang in Feldman (1998) Gastrointestinal, p. 1793-7
    3. Hammond (2010) Am Fam Physician 82(7): 766-70
    4. Salzman (2005) Am Fam Physician 72:1229-42
    5. Stollman (2004) Lancet 363(9409): 631-9