Continuity of Care: Diverticulitis: Seeping into New Patient Populations

Ms. Wick is a senior clinical researchpharmacist at the National CancerInstitute, National Institutes ofHealth, Bethesda, Maryland. Theviews expressed are those of theauthor and not those of any governmentagency.

Almost unheard of in developingnations, colonic diverticulardisease is common inWestern and industrialized societies. Arelatively new disease, it is rarely mentionedin documents predating WorldWar I. The condition surfaced whenprocessed foods were introduced intothe American diet.

Diverticulosis describes the presenceof uninflamed mucosal herniationsor sacs (diverticula) in the colonwall. These small pouches bulge outwardthrough weak spots—similar toan inner tube poking through weakplaces in a tire. Diverticulosis is largelysymptomless; however, up to threequarters of patients may have sensitiveor unpredictable bowel habits.

Diverticulitis indicates inflameddiverticula, often accompanied bygross or microscopic perforations. Upto one quarter of people with diverticulumdevelop diverticulitis.^1-4 Diverticulitisaffects the sigmoid and descendingcolon (located on patient'sleft side) in >90% of patients⁵ and alsois a relatively common cause of acutelower gastrointestinal bleeding. Patientsmay report blood in their stool.⁶

Patients are being diagnosed withdiverticulitis with greater frequency,partly because age and obesity arecontributing factors. Approximately130,000 Americans, generally olderthan age 50 (a population that is growingin number), with equal gender distribution,are hospitalized with diverticulardisease annually.^1-4 It has beenidentified as one of the 5 most costlygastrointestinal diseases.⁷ Long regardedas a disease of the elderly, the incidenceof diverticulitis has been increasingin those under age 40, especiallyin men and the obese.⁸

The musculature of the colon thickenswith age, reflecting increasingpressures required to eliminate feces.Patients with diverticulosis often presentwith increased intracolonic pressureas the left colon narrows due todiverticulum formation.^9,10 Diverticulosishas been associated with diets low indietary fiber but high in refined carbohydrates,which create smaller, harderstools and may slow gastrointestinaltransit time; its exact cause is stillunknown.^11,12 Slow transit time canincrease intracolonic pressure andmake bowel evacuation difficult.²Constipation, obesity, physical inactivity, smoking, and treatment with nonsteroidalanti-inflammatory drugs alsohave been associated with diverticulardisease.⁷

Adverse Outcomes

Should colonic diverticula becomeobstructed with fecal matter, severaladverse outcomes may follow: sac distention,bacterial overgrowth, vascularcompromise, local-tissue ischemia,and perforation. Although perforationscan be localized and contained, somemay invade the skin or erode adjacentviscera, causing fistulas especiallyamong the colon, small intestine, skin,and bladder.

The chain of events is similar to thatin appendicitis, and diverticulitis isoften mistaken for appendicitis. Anaerobesare isolated most often, but gramnegativeaerobes, especially Escherichiacoli, and facultative gram-positive bacteria,like streptococci, also are found.¹³Complicated diverticulitis describes anabscess or spreading, diffuse inflammatoryreaction, fistula formation,stricture disease, bowel obstruction, orperitonitis.

Presentation

In classic cases, patients who developdiverticulitis report severe constipationand abdominal pain in the leftlower quadrant and present withleukocytosis and low-grade fever.Abdominal or perirectal fullness maybe palpable, and patients may complainof bloating. Patients with perforationhave marked abdominal tendernessthat begins suddenly and spreadsrapidly to involve the entire abdomen,causing perotinitis.^2,14

Several populations tend to presentatypically. Asians, including Asian Americans,have a predominance of rightsideddiverticula. In immunocompromisedpatients, diverticulitis is generallymore severe and may present withatypical signs and symptoms. Thesepatients are more likely to have perforations,are less likely to respond toconservative management, and havehigher postoperative risks than immunocompetentpatients.^2,14 Youngerpatients also are likely to present withatypical symptoms.⁶

Staging

Hinchey's criteria are used to classifydiverticulitis into 4 stages (Table).More severe forms of diverticulitis areoften accompanied by anorexia, andrisk of death increases from 13% instage 3 to 43% in stage 4.¹⁵ When acutediverticulitis is suspected, cliniciansavoid using colonoscopy and sigmoidoscopy,which increase the perforationrisk that can exacerbate disease.Computed tomography accurately identifiesmost cases of diverticulitis.^16,17

Diverticulosis and diverticulitis aretreated differently in different healthcare settings, and the conditions arechronic in nature. Understanding howexacerbations are handled in each settingcan help pharmacists ensure continuityof care.

References

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