Diverticulitis

78  Diverticulitis

ICD-10 CODE K57.32

THE CLINICAL SYNDROME Diverticulitis is a common cause of acute abdominal pain in western and industrialized countries. Found more commonly in women, the disease occurs more commonly after the forth decade. Diverticulitis occurs when small herniations of the colonic mucosa and submucosa, known as diverticula, become inflamed or tear (Fig. 78.1). It is estimated that approximately 75% of patients will have diverticula by the age of 80, as there is age-related weakening of the abdominal wall in areas of insertion of the vasa recta. Decrease bowel motility of senescence may also play a role in increasing intracolonic pressure, as may changes in the microbiome of the gastrointestinal tract. Patients with diverticulitis will develop abdominal pain that is usually located in the left lower quadrant, although there is an increased incidence of right-sided diverticular disease in Asians (Fig. 78.2). Constipation is present approximately 50% of the time, with diarrhea occurring in 25% of patients suffering from acute diverticulitis. Abdominal tenderness is invariably present as are fever and chills. The pain of diverticulitis is proportional to the extent of inflammation, with the pain ranging from mild, intermittent pain to severe, unremitting pain with frank signs of peritonitis including rebound tenderness. Lower gastrointestinal bleed, which may be significant, may also be present. Factors that increase the risk of developing diverticulitis include advancing age, low-fiber high-fat diet, obesity, smoking, and the use of corticosteroids and nonsteroidal antiinflammatory agents. Diets high in vitamin D and the use of statins

FIG 78.1  Diverticulosis on colonoscopy. (From Feuerstein JD, Falchuk KR. Diverticulosis and diverticulitis. Mayo Clin Proc. 2016;91(8):1094–1104.)

and calcium channel blocker may exert a protective effect. Mild cases of diverticulitis are managed conservatively, but approximately 25% of patients with acute diverticulitis will develop complications that may include abscess formation, bowel obstruction, peritonitis, and sepsis.

SIGNS AND SYMPTOMS Left-sided abdominal pain is present in most patients with acute diverticulitis, although patients of Asian descent have an increased incidence of right-sided diverticulitis, which may mimic acute appendicitis. The pain of acute diverticulitis is associated with anorexia and a change in bowel habits and

FIG 78.2  The patient with acute diverticulitis will suffer from left-sided abdominal pain associated with a change in bowel habits. Fever and chills are often present.

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SECTION X  Abdominal and Groin Pain Syndromes

FIG 78.3  Computed tomography scan (anterior, posterior, and coronal views) showing colovesical fistula. (From Chapman JR, Wolff BG. The management of complicated diverticulitis. Adv Surg. 2006;40:285–297.)

gastrointestinal symptoms of constipation, diarrhea, bloating, flatulence, and nausea and vomiting. A small percentage of patients will complain of urinary urgency and frequency secondary to irritation of the adjacent urinary tract. Often the patient will flex the hip on the affected side owing to irritation of the psoas muscle. Mild diverticulitis may produce minimal constitutional symptoms, but if the disease progresses, fever and chills may be pronounced. On physical examination, the extent of abdominal findings will be in proportion to the extent of the diverticulitis. Small microperforations of left-sided diverticula will produce diffuse left lower quadrant pain with minimal peritoneal findings. With more severe diverticulitis, the pain will become more localized to the left lower quadrant and pelvis with rebound tenderness a prominent physical findings. If a peridiverticular abscess or phlegmon forms, a tender, palpable mass may be identified. The abdomen may be distended and tympanic to percussion, with bowel sounds diminished or absent. If a fistula into the genitourinary tract forms, fecaluria or pneumaturia may be present with colovaginal fistulas occurring in females (Fig. 78.3).

TESTING Computed tomography of the abdomen and pelvis has replaced barium enema as the preferred imaging modality to diagnose diverticulitis because not only can it diagnose the disease with a high degree of specificity and sensitivity, but can also identify complications as well as pericolonic abscess and other pathologic processes that may mimic the diverticulitis. The Hinchey classification can help define the severity of complicated diverticulitis and guide treatment (Table 78.1 and Fig. 78.4). Colonoscopy can also diagnose diverticulitis, but cannot identify potential serious complications as intraabdominal or retroperitoneal abscess or fecal peritonitis. Based on the patient’s clinical presentation, additional testing, including a complete blood count to identify leukocytosis with a left shift, urinalysis, and serum chemistries are indicated. Blood cultures should be obtained if fever is present. A pregnancy test must be obtained on all females of child-bearing age to rule out ectopic pregnancy. If abscess formation is suspected, imaging of adjacent structures (e.g., hip, bladder) should be obtained sooner than later.

FIG 78.4  A, Modified Hinchey stage III diverticulitis. Arrow points to free fluid. B, Modified Hinchey stage III diverticulitis. Arrow points to free air. C, Modified Hinchey stage III diverticulitis. Demonstrates intraabdominal free fluid. D, Modified Hinchey stage III diverticulitis. Arrow points to pelvic fluid. (From Hall J, Hammerich K, Roberts P. New paradigms in the management of diverticular disease. Curr Probl Surg. 2010;47(9):680–735.)

TABLE 78.1  Stage I Stage II Stage III Stage IV

Pericolic abscess or phlegmon Pelvic, intraabdominal, or retroperitoneal abscess Generalized purulent peritonitis Generalized fecal peritonitis

BOX 78.1  Diseases That May Mimic

Acute Diverticulitis

Appendicitis Inflammatory bowel disease Irritable bowel syndrome Colorectal malignancies Acute gastroenteritis Ectopic pregnancy Ischemic colitis Abdominal angina Tubo-ovarian abscess Pelvic inflammatory disease Ureteral calculi Volvulus Ovarian torsion Endometriosis

DIFFERENTIAL DIAGNOSIS Most causes of acute abdominal pain can mimic the diverticulitis and are listed in Box 78.1. Most commonly, acute gastroenteritis, inflammatory bowel disease, irritable bowel syndrome, ectopic pregnancy, ischemic colitis, and mesenteric

CHAPTER 78  Diverticulitis

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COMPLICATIONS AND PITFALLS Many other causes of an acute abdomen can mimic the presentation of diverticulitis. The failure to correctly identify the source of the patient’s abdominal symptoms can lead to significant morbidity and mortality. It should be remembered that right-sided diverticulitis is common in patients of Asian descent and may present identically to acute appendicitis. Early identification and drainage of abscess is essential to avoid more serious complications when treating diverticulitis.

CLINICAL PEARLS FIG 78.5  Diverticular abscess. A, Diagnostic computed tomography. B, Percutaneous drain placed. C, Intraoperative resection of bowel with percutaneous drain in place. (From Chapman JR, Wolff BG. The management of complicated diverticulitis. Adv Surg. 2006;40:285–297.)

artery ischemia are misdiagnosed as diverticulitis. Acute appendicitis can also mimic right-sided diverticulitis.

TREATMENT The treatment of diverticulitis is based on the severity of the disease and must be individualized to the specific patient. In uncomplicated diverticulitis presenting with mild symptoms, patients are treated with a clear liquid diet for 7 to 10 days and oral broad-spectrum antibiotics, such as ciprofloxacin and metronidazole, that cover anaerobic microorganisms. Opioids should be avoided, as they decrease bowel motility. For patients with more severe symptomatology, including fever and chills, the immediate use of broad spectrum intravenous antibiotics and the drainage of any abscess are mandatory (Fig. 78.5). If the abscess cannot be drained percutaneously, or if significant perforation, fistula, or bowel obstruction is present, emergent surgical treatment consisting of primary bowel resection is indicated. Occasionally, a diverting colostomy will be required to allow resolution of severe diverticulitis.

Diverticulitis is a common cause of acute abdominal pain. Its clinical presentation can range from a mild self-limited disease to a life-threatening illness. Because of the number of other diseases that mimic diverticulitis, diagnosis and treatment may be delayed, leading to increased morbidity and, rarely, mortality. Early implementation of broad-spectrum antibiotics and identification and drainage of pericolonic abscess are mandatory to decrease more serve complications.

SUGGESTED READINGS Ferrara F, Bollo J, Vanni LV, et al. Diagnosis and management of right colonic diverticular disease: a review. Cir Esp. 2016;94(10):553–559. Feuerstein JD, Falchuk KR. Diverticulosis and diverticulitis. Mayo Clin Proc. 2016;91(8):1094–1104. Horesh N, Wasserberg N, Zbar AP, et al. Changing paradigms in the management of diverticulitis. Int J Surg. 2016;33(Pt A):146–150. Peery AF, Keku TO, Martin CF, et al. Distribution and characteristics of colonic diverticula in a United States screening population. Clin Gastroenterol Hepatol. 2016;14(7):980–985. Roig JV, Salvador A, Frasson M, et al. Surgical treatment of acute diverticulitis. A retrospective multicentre study. Cir Esp. 2016;94(10):569–577. Tan JPL, Barazanchi AWH, Singh PP, et al. Predictors of acute diverticulitis severity: a systematic review. Int J Surg. 2016;26:43–52.