
Am Fam Physician. 2022;106(2):150-156
Author disclosure: Dr. Dattani reports serving as a proctor for Intuitive Surgical. Drs. Bailey and Jennings have no relevant financial relationships.
Diverticulitis should be suspected in patients with isolated left lower quadrant pain, abdominal distention or rigidity, fever, and leukocytosis. Initial laboratory workup includes a complete blood count, basic metabolic panel, urinalysis, and C-reactive protein measurement. Computed tomography with intravenous contrast is the preferred imaging modality, if needed to confirm diagnosis and assess for complications of diverticulitis. Treatment decisions are based on the categorization of disease as complicated vs. uncomplicated. Selected patients with uncomplicated diverticulitis may be treated without antibiotics. Complicated diverticulitis is treated in the hospital with modified diet or bowel rest, antibiotics, and pain control. Abscesses that are 3 cm or larger should be treated with percutaneous drainage. Emergent surgery is reserved for when percutaneous drainage fails or the patient's clinical condition worsens despite adequate therapy. Colonoscopy should not be performed during the flare-up, but should be considered six weeks after resolution of symptoms in patients with complicated diverticulitis who have not had a high-quality colonoscopy in the past year. Diverticulitis prevention measures include consuming a vegetarian diet or high-quality diet (high in fruits, vegetables, whole grains, and legumes), limiting red meat and sweets, achieving or maintaining a body mass index of 18 to 25 kg per m2, being physically active, and avoiding tobacco and long-term nonsteroidal anti-inflammatory drugs. Partial colectomy is not routinely recommended for diverticulitis prevention and should be reserved for patients with more than three recurrences or abscess formation requiring percutaneous drainage.
A diverticulum is a protrusion through the intestinal wall, and diverticulosis is the presence of multiple diverticula. Acute diverticulitis is inflammation of diverticula. Possible causes include abnormal colonic motility, colonic wall resistance, intraluminal pressures, and colonic wall defects.1,2 Diverticular bleeding, the most common cause of lower gastrointestinal tract bleeding in adults, was reviewed previously in American Family Physician (https://www.aafp.org/afp/2009/1101/p977.html). The current article provides a summary of the best evidence on diagnosis and management of diverticular disease.

Epidemiology
Incidence of diverticulitis is increasing. From 1980 to 2007, the incidence increased from 115 per 100,000 person-years to 188 per 100,000 person-years.3
Prevalence of diverticular disease is less than 10% in people 40 years vs. 80% in those older than 85 years.1,2 [corrected]
Only 1% to 4% of patients with diverticular disease will develop diverticulitis in their lifetime.4
Risk factors for diverticular disease include increasing age, constipation, low-fiber diet, smoking, red meat consumption, obesity, weight gain, lack of exercise, genetic susceptibility, and nonsteroidal anti-inflammatory drug and aspirin use.1,5,6
Consumption of popcorn, nuts, and seeds is not a risk factor for developing diverticulitis.7
Screening and Prevention
Screening for diverticular disease is not recommended. It is often found incidentally on screening colonoscopy or imaging studies performed for other reasons.
Measures for preventing recurrence of diverticulitis include consuming a vegetarian diet or high-quality diet (high in fruits, vegetables, whole grains, and legumes), limiting red meats and sweets, achieving or maintaining a body mass index of 18 to 25 kg per m2, being physically active, and avoiding tobacco and long-term nonsteroidal anti-inflammatory drugs.8–11
A high-fiber diet is associated with a lower incidence of diverticular disease, but evidence regarding whether it prevents the recurrence of diverticulitis is lacking.12
Diagnosis
SIGNS AND SYMPTOMS
Tenderness to palpation located only in the left lower quadrant of the abdomen is the most specific finding for diverticulitis (likelihood ratio [LR] = 10.4). Tenderness in the left lower quadrant plus other locations is less useful (LR = 3.4).13
History of left lower quadrant tenderness (LR = 3.3), fever (LR = 1.4), and absence of vomiting (LR = 1.4) also support the diagnosis13 (Table 11).
Other nonspecific signs and symptoms may include abdominal rigidity, anorexia, dysuria, hypoactive bowel sounds, rectal bleeding, or tenderness on rectal examination.1,13
Fecaluria, pneumaturia, pyuria, and stool per vagina should raise suspicion for fistula formation.8
Studies have found that right-sided diverticulitis is more common in Asian countries.14
The differential diagnosis of diverticulitis is shown in Table 2.1

Signs and symptoms | LR+ | LR− |
---|---|---|
Localized tenderness only in the left lower quadrant | 10.4 | 0.7 |
History of left lower quadrant pain | 3.3 | 0.5 |
Absence of vomiting | 1.4 | 0.2 |
History of fever | 1.4 | 0.8 |
Laboratory or imaging findings | ||
Computed tomography* | 94 | 0.1 |
Ultrasonography* | 9.2 | 0.09 |
Magnetic resonance imaging* | 7.8 | 0.07 |
C-reactive protein level > 5 mg per dL (50 mg per L) | 2.2 | 0.3 |
Combination of left lower quadrant pain, the absence of vomiting, and a C-reactive protein level > 5 mg per dL | 18 | 0.65 |

Gastrointestinal Bowel obstruction Colitis (infectious and ischemic) Colon cancer Inflammatory bowel disease Irritable bowel syndrome Perforation | Gynecologic Ectopic pregnancy Endometriosis Ovarian cyst Pelvic inflammatory disease Torsion Tubo-ovarian abscess | Urinary Nephrolithiasis Urinary tract infection |
DIAGNOSTIC EVALUATION
Initial tests include complete blood count (white blood cell count may be normal in 45% of patients), basic metabolic panel to evaluate electrolyte and renal status, urinalysis to rule out urinary tract infection, and C-reactive protein (level greater than 20 mg per dL [200 mg per L] is suggestive of perforation).13
Other tests to consider in selected patients include a beta-human chorionic gonadotropin test to rule out ectopic pregnancy and if surgery is needed in a patient who could become pregnant, and a lipase test to rule out acute pancreatitis (mild elevation of lipase may occur with perforation).
Imaging should be considered if the diagnosis is uncertain or there is concern for complicated diverticulitis.
If imaging is performed, computed tomography with contrast is the diagnostic test of choice because of its availability and high sensitivity (94%) and specificity (99%).8,9,15,16
Magnetic resonance imaging has good diagnostic accuracy and avoids radiation exposure but may not be as readily available as computed tomography.8,17
Ultrasonography can be effective in the diagnosis of diverticulitis, but operator experience affects accuracy. Its ability to assess for free air or the extent of large abscesses is limited.8,17
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