11.8 Diverticulitis
A diverticulum is an out-pouching of the wall of the colon. The presence of many diverticula is known as diverticulosis. Clients with diverticulosis are generally asymptomatic, but a small percentage develop diverticulitis, inflammation of a diverticulum.[1],[2] See Figure 11.28[3] for an image of a colon with diverticulosis.
Diverticulitis can be complicated or uncomplicated. Uncomplicated diverticulitis means there is inflammation with no complications present. Complicated diverticulitis refers to diverticulitis associated with an abscess, perforation, fistula (an abnormal connection between two organs), or a bowel blockage.[4],[5]
Risk factors for diverticulosis and diverticulitis are the same, with the main risk factors being dietary intake. Clients with low-fiber intake or high intake of red meat and fatty foods are at increased risk for developing diverticulosis and diverticulitis. Other risk factors include obesity, tobacco usage, certain medications (NSAIDs, steroids, opioids and statins), and age, with 60% of clients aged 60 or older having diverticulosis.[6],[7]
Pathophysiology
Diverticula form where the walls of the colon are weak. This weakness occurs due to increased pressures in the colon or a result of connective tissue disorders. Constipation and the straining that occurs during bowel movements can play a role in diverticula forming due to the increased pressure within the colon.[8],[9],[10]
Obstruction from hardened stool or food eroding the wall of the diverticula causes inflammation and necrosis of the diverticulum, which lead to the perforation. Perforation can cause diverticulitis, which can also lead to formation of an abscess, fistula, or bowel obstruction. Major perforations can cause peritonitis.[11],[12],[13]
Assessment
Physical Exam
Clients with diverticulosis are often asymptomatic. However, blood may be present in the stool because diverticula bleed easily.
Clients with diverticulitis commonly present with abdominal pain, typically in the left lower quadrant. Clients may also experience altered bowel habits such as diarrhea or constipation. Fever, nausea, and vomiting may also be present.
When completing a physical exam, if an abscess is present, the provider may be able to palpate a mass. Bowel sounds are commonly hypoactive.
Common Laboratory and Diagnostic Tests
Lab Tests
Labs tests ordered to diagnose diverticulitis are a complete blood count and inflammatory markers[14],[15]:
- Complete blood count (CBC) will often show elevated white blood cells.
- Inflammatory markers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are often elevated during diverticulitis.
Review normal reference ranges for common diagnostic tests in “Appendix A – Normal Reference Ranges.”
Imaging
Imaging modalities used to diagnose diverticulosis and diverticulitis are CT scan, abdominal ultrasound, and colonoscopy[16],[17]:
- A CT scan of the abdomen with contrast is considered the gold standard f