Diverticula are sac-like protrusions in the wall of the colon. Rarely, they are congenital and involve all layers of the colon wall. Pseudodiverticula, the more common acquired form, are herniations that extend through the mucosa, the submucosa, and into the circular muscular coat. Most diverticula occur in the sigmoid colon (95%). The presence of many diverticula along the bowel wall is called diverticulosis. Diverticulitis is the inflammation of one or multiple diverticula that often results in a microperforation or macroperforation of the bowel. It occurs in 15% to 20% of patients with diverticula. It may be a localized inflammation or can involve free perforation or peritonitis. The sequelae of diverticular disease (see section on Complications/Sequelae) can be very serious and typically require surgery.

According to epidemiologic studies, diverticulitis is significantly more common in countries with Western, low-fiber diets. Prevalence in the United States is estimated at 10%. However, more than 50% of autopsied adults over the age of 60 have diverticula.

The etiology is presumed to be multifactorial but not clearly understood. Factors potentially contributing to the initiation of changes in the colonic wall include aging, colonic motility, abnormal changes in intraluminal pressure, low-fiber diets, and various anatomic defects.

• Low-fiber, Western diet
• Aging
• Obesity
• Men—for diverticulitis

Diverticula

• Often asymptomatic
• Mild irregularities in defecation

Diverticulitis

• Left lower quadrant pain is classic, often following a meal; may have abdominal pain in other locations.
• Painless rectal bleeding, hematochezia, hemorrhage—usually from the right colon; 15% to 40% of patients; 25% to 50% of the time, microscopic blood is found on exam.
• Fever
• Nausea, vomiting
• Constipation, diarrhea
• Flatulence
• Fistulas—urinary tract infection, pneumaturia, dysuria, frequency
• Peritonitis—acute onset abdominal pain, muscle spasm, guarding, possibly sepsis

• Irritable bowel syndrome
• Colorectal cancer
• Inflammatory bowel disease
• Appendicitis
• Angiodysplasia

Diverticulitis

• Left lower quadrant tenderness
• Abdominal distention
• Percussion tenderness, guarding—indicates peritonitis
• Palpable mass possible
• Fever >101°F

Diverticulitis

• Complete blood cell count—white blood cells (WBC) usually elevated (>15,000); predominance of polymorphonuclear leukocytes
• Urinalysis—WBC predominate with inflammation adjacent to bladder or ureter; bacteria indicate fistula.
• Stool—reveals occult blood in 25% to 50% of cases.

• Diverticula form between mesenteric and lateral teniae, especially at area of greatest muscular weakness where the intramural vasa recta penetrate the circular muscle to the submucosa.
• Increased muscle layer thickening causes teniae to shorten, narrowing the colonic lumen and permitting muscle contractions that divide the bowel into isolated segments; hypersegmentation results in intraluminal hypertension ³90 mm Hg, causing mucosal herniation.
• Fecalith erodes or becomes impacted in the mucus lining, rendering it susceptible to bacterial invasion and causing inflammation (localized, which can become generalized to peritonitis).
• Healed diverticula can leave segmental narrowing, stricture, or obstruction.

• Computed tomography—locates inflammation, abscesses, obstruction, fistulae; assists with percutaneous abscess drainage.
• Barium enema—shows diverticula, fistulae, abscesses; risk of generalized peritonitis limits its use during acute attack of diverticulitis.
• Ultrasound—reveals inflammation, diverticula, abscesses; assists with percutaneous drainage.

• Colonoscopy—localizes diverticula; differentiates colorectal cancer; evaluates acute hematochezia.
• Angiography—localizes diverticula during profuse bleeding.

With mild symptoms, outpatient treatment includes clear liquid diet and oral broad-spectrum antibiotics. Inpatient treatment includes bowel rest by administration of total parenteral nutrition and intravenous broad-spectrum antibiotics. Patients improving within 72 hours can resume oral diet and are discharged with oral antibiotics. High-fiber diets and psyllium supplements are recommended following acute episode. Within 6 weeks, colonoscopy or barium enema is performed. Elective surgery is recommended if attacks recur; generally, surgery is performed once an acute attack has resolved. Patients under 40 (more aggressive disease), who deteriorate within 24 to 48 hours, or those who have severe complications, are treated urgently with surgery.

• Broad-spectrum antibiotic therapy—cefoxitin 2 to 3 g IV q8hr; metronidazole 500 mg IV q6hr with an aminoglycoside for more severe cases; either TMP/SMX 160 mg/800 mg po bid or amoxicillin 500 mg tid or ciprofloxacin 500 mg po bid, plus metronidazole 500 mg po q 6 hours for outpatient
• Anticholinergics—relieve cramping, but risk of constipation
• Analgesics—avoid narcotics if possible, especially morphine which causes colonic spasm; meperidine use acceptable

• Colonoscopy—electrocoagulation of arterial venous malformations or angiodysplasias; its use with epinephrine injections and/or bipolar coagulation decreases risk of severe hemorrhage
• Sigmoidectomy—one-step operation performed after bowel preparation; done laparoscopically in uncomplicated cases
• Hartman's procedure—commonly used for emergency surgery; resection with sigmoid colostomy and rectal stump closure; colostomy reversed in second operation within 6 months; lowers mortality by reducing sepsis
• Angiography—therapy at diagnosis includes intra-arterial infusions of vasopressin (0.2 U/min for 6 to 12 hours) or selective embolization to temporarily control bleeding; treatment failure associated with higher mortality because of surgical delay

Nutrition plays an important role in the prevention and treatment of gastrointestinal disease in general and development of diverticulosis in particular. Specific dietary factors have been correlated with the incidence of diverticular disease and may play a role in minimizing exacerbations and improving outcome.

High-Fiber Diet

Epidemiological studies suggest that high dietary fiber consumption is protective against the development of diverticular disease and other gastrointestinal disorders. A review of epidemiological studies reports that vegetarians have a decreased incidence of diverticular disease, most likely due to increased intake of dietary fiber (Nair and Mayberry 1994).

An epidemiological study in Greece matched 100 consecutive patients who had radiographically confirmed diverticular disease against 110 control patients with no presence of diverticulosis, gastrointestinal disorders, or significant abdominal symptoms. A structured interview and a food frequency questionnaire were administered to all subjects. A statistically significant protective association was found between the following foods and diverticular disease:

• Cucumber
• Lettuce
• Spinach
• Brown bread

Foods that were significantly detrimental were beef and lamb. The authors concluded that in addition to increasing fiber intake, lowering risk of the disease requires (Manousos et al. 1985):

• Decreasing the consumption of red meat, particularly lamb and beef
• Reducing intake of milk and milk derivatives, although not as important as reduction of meat ingestion

Other Lifestyle Factors

While epidemiological studies link increased consumption of dietary fiber with decreased risk of diverticular disease, there is less conclusive evidence about the impact of other lifestyle factors. Findings from a prospective study of 47,678 men, 40 to 75 years old, who were enrolled in the U.S. Health Professionals Follow-Up Study showed that 500 subjects developed diagnoses of diverticular disease during 4 years of follow-up; 382 of these were classified as symptomatic. Investigators found little or no relationship between the following and development of symptomatic diverticular disease:

• Smoking
• Consumption of caffeine
• Moderate alcohol intake

Although there was no overall association between smoking and diverticular disease, smokers in the highest category (³40 pack-years) did have a 21% greater risk of developing the disease compared to those who had never smoked. The authors suggest, though, that this connection may actually be due to:

• Dietary fiber intake
• Level of physical activity
• Amount of dietary fat consumed

In other words, smoking does not appear to be an independent risk factor for diverticulosis (Aldoori et al. 1995).

Glutamine

The relationship of specific micronutrients to diverticular disease has not been evaluated as thoroughly as generalized dietary and lifestyle trends. Glutamine, though, may prove beneficial in the prevention and treatment of diverticular disease through the following mechanisms (Murray 1996):

• Prevention of colonic mucosal atrophy
• Reduced macromolecule permeability
• Inhibition of the rate of bacterial translocation to mesenteric lymph nodes

Short-Chain Fatty Acids

Short-chain fatty acids (SCFAs) are thought to be essential for normal colonic mucosal function:

• Butyrate
• Isobutyrate
• Propionate
• Acetate

SCFAs are not obtained through the diet but are produced by the action of anaerobic bacteria on undigested carbohydrates (e.g., resistant starch or dietary fiber). Certain fibers increase the levels of SCFAs produced in the colon more effectively (Murray 1996). These dietary fiber products include:

• Apple and citrus pectin
• Guar gum
• Legumes

Butyrate, in particular, is thought to have a stabilizing effect on colonic mucosa, serving as a respiratory fuel for colonic epithelia, and enhancing cellular growth, proliferation, and differentiation (O'Keefe 1996).

Omega-3 Essential Fatty Acids

Omega-3 essential fatty acids found in flax and fish have anti-inflammatory properties while omega-6 fatty acids found in meats and dairy products are pro-inflammatory. To prevent or treat a condition such as diverticulitis, it seems prudent to follow a diet rich in omega-3 fatty acids. Another benefit for this nutritional plan is that studies suggest that it is a good diet for preventing colon cancer (O'Keefe 1996).

Certain herbs are used for the beneficial effects of their fiber content:

• Psyllium seed (Plantago ovata and Plantago psyllium) is recommended by the World Health Organization (WHO) to relieve diverticulitar associated constipation (Blumenthal et al. 2000).
• Flaxseed (Linum usitatissimum) is approved by the German Commission E as part of the treatment for diverticulosis (Blumenthal et al. 2000).

Although there is anecdotal information about the value of homeopathy for prevention and treatment of gastrointestinal disorders including diverticular disease, this has not been adequately studied to date. An experienced homeopath, though, will consider an individual's constitution and collection of symptoms and may recommend some of the following remedies:

• Belladonna—for abdominal pain and cramping that come on suddenly and are relieved by firm pressure; especially with constipation
• Bryonia—for abdominal pain that is worse with movement and is alleviated by heat; especially with vomiting, constipation, and dry, hard stools
• Colocynthis—for cutting, cramping abdominal pains that are better with pressure; especially when accompanied by restlessness and diarrhea
  
  

• Patients should report fever, tenderness, or bleeding immediately.
• Patients with fever >101°F, deterioration, signs of peritonitis, or increased WBC count should be hospitalized for initial treatment.

• High-fiber diet (15 g/day)—increases stool weight and transit time, decreases colonic pressure
• Avoid foods (e.g., seeds) that block the mouth of the diverticulum.
• Exercise—tends to decrease incidence of symptoms

• Abscess—most frequent complication
• Obstruction—can mimic neoplasm
• Free perforation—acute peritonitis, sepsis, shock; elderly most vulnerable
• Fistulas—abscesses that erode into adjacent organs, requires prompt control of sepsis
• Bleeding—70% stop spontaneously; resuscitative measures and blood transfusions required before surgery

• Diverticulitis—30% of patients have second episodes; 50% of those having second attacks have third attacks
• Complications—20% of patients after first attack, 60% after second attack
• Elective surgery—2% mortality rate
• Purulent peritonitis 5% mortality rate, feculent peritonitis 35%
• Risk of bleeding—50% after second hemorrhage

• May need to be differentiated from ectopic pregnancy at the time of presentation

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