Diverticulosis

Overview

Diverticulosis represents one of the most prevalent conditions affecting the digestive system in Western countries. The formation of diverticula occurs when weak spots in the colon wall give way under pressure, causing the inner layer of the intestine to push through and form small pouches. These pouches typically range from 5 to 10 millimeters in diameter but can occasionally grow larger. The condition is often discovered incidentally during routine colonoscopy or imaging studies performed for other reasons.

The prevalence of diverticulosis has increased significantly over the past century, particularly in industrialized nations. This rise is closely associated with dietary changes, specifically the adoption of low-fiber, highly processed diets. In the United States, approximately 35% of adults under 50 have diverticulosis, while this percentage increases to 58% in those over 60. The condition shows interesting geographical variations, being rare in rural Africa and Asia where high-fiber diets are common, but increasingly prevalent as these populations adopt Western dietary habits.

While diverticulosis itself is often asymptomatic, it can lead to several complications. About 10-25% of people with diverticulosis will develop diverticulitis, an inflammatory condition that can cause significant pain and require medical intervention. Other potential complications include diverticular bleeding, which accounts for a significant proportion of lower gastrointestinal bleeding in older adults, and rarely, perforation or abscess formation. Understanding diverticulosis is crucial for preventing these complications and maintaining digestive health as we age.

Symptoms

Most people with diverticulosis have no symptoms and are unaware of the condition. However, when symptoms do occur, they can range from mild discomfort to more serious manifestations requiring medical attention. The presence and severity of symptoms often depend on the location and number of diverticula, as well as whether complications have developed.

Abdominal Symptoms

• Lower abdominal pain - Most commonly in the left lower quadrant, may be crampy or constant
• Sharp abdominal pain - Sudden, severe pain may indicate complications
• Upper abdominal pain - Less common but can occur with proximal diverticula
• Bloating and gas - Feeling of fullness or distension
• Tenderness when pressure applied to abdomen
• Change in bowel habits - Alternating between normal and abnormal patterns

Gastrointestinal Symptoms

• Blood in stool - May appear as bright red or dark, tarry stools
• Rectal bleeding - Often painless, can be profuse in diverticular bleeding
• Melena - Black, tarry stools indicating upper GI or slow lower GI bleeding
• Diarrhea - May alternate with constipation
• Constipation - Often chronic, may worsen the condition
• Narrow stools - Due to colonic spasm or inflammation

Associated Symptoms

• Nausea - May accompany abdominal discomfort
• Vomiting - More common with complications like obstruction
• Heartburn - May occur due to associated digestive issues
• Fever - Suggests inflammation or infection (diverticulitis)
• Urinary symptoms - Frequency or urgency if inflamed colon irritates bladder
• Fatigue - May result from chronic bleeding or inflammation

Warning Signs

Certain symptoms require immediate medical attention as they may indicate serious complications:

• Severe, persistent abdominal pain
• High fever with chills
• Significant rectal bleeding
• Persistent vomiting
• Signs of peritonitis (rigid abdomen, severe tenderness)
• Inability to pass gas or have bowel movements

Causes

The exact cause of diverticulosis is not fully understood, but several factors contribute to the development of diverticula in the colon wall. The condition results from a complex interaction of dietary, lifestyle, and anatomical factors that affect colonic pressure and wall integrity.

Primary Mechanisms

• Increased colonic pressure: High pressure within the colon, particularly during constipation and straining, pushes the inner lining through weak spots in the muscle wall
• Weakened colon wall: Age-related changes in connective tissue and muscle tone create vulnerable areas
• Segmentation: Excessive muscle contractions create isolated high-pressure zones
• Structural factors: Natural weak points where blood vessels penetrate the colon wall

Dietary Factors

• Low-fiber diet: Primary dietary risk factor in Western populations
  • Reduces stool bulk and increases transit time
  • Requires more pressure to move stool through colon
  • Associated with constipation and straining
• Refined foods: Processed foods lacking natural fiber
• Red meat consumption: High intake associated with increased risk
• Low fluid intake: Contributes to constipation and hard stools

Age-Related Changes

• Collagen changes: Decreased elasticity and increased cross-linking
• Muscle wall thickening: Compensatory response to increased pressure
• Elastin degradation: Loss of elastic fibers in colon wall
• Nerve changes: Altered motility patterns with aging

Lifestyle and Behavioral Factors

• Physical inactivity: Sedentary lifestyle affects bowel motility
• Obesity: Increases intra-abdominal pressure
• Smoking: May affect colonic blood flow and tissue integrity
• Chronic constipation: Long-term straining weakens colon wall
• Heavy lifting: Repeated increases in abdominal pressure

Genetic and Other Factors

• Genetic predisposition: Family history increases risk
• Connective tissue disorders: Ehlers-Danlos, Marfan syndrome
• Medications: NSAIDs, steroids may increase complication risk
• Geographic variation: Higher prevalence in Western countries

Risk Factors

Several factors increase the likelihood of developing diverticulosis:

• Age: Most significant risk factor
  • Rare before age 40
  • 50% prevalence by age 60
  • 70% prevalence by age 80
• Diet:
  • Low dietary fiber intake (less than 25-30g daily)
  • High consumption of red meat and fat
  • Low fruit and vegetable intake
  • Western dietary pattern
• Obesity: BMI over 30 increases risk by 30-40%
• Physical inactivity: Sedentary lifestyle doubles risk
• Smoking: Current and former smokers at higher risk
• Medications:
  • Regular NSAID use
  • Corticosteroids
  • Opioid analgesics
• Genetics: Family history increases risk 3-fold
• Gender: Slightly more common in women in Western countries
• Ethnicity: Higher in Caucasians than African Americans in US
• Chronic constipation: Long-standing bowel dysfunction
• Connective tissue disorders: Increased susceptibility
• Previous abdominal surgery: May alter bowel function

Diagnosis

Diverticulosis is often discovered incidentally during examinations for other conditions. When symptoms are present, various diagnostic methods help confirm the diagnosis and rule out complications or other conditions with similar presentations.

Clinical Evaluation

• Medical history: Symptoms, dietary habits, bowel patterns, family history
• Physical examination:
  • Abdominal palpation for tenderness or masses
  • Digital rectal examination
  • Vital signs to check for fever or signs of bleeding

Imaging Studies

• Colonoscopy: Gold standard for diagnosis
  • Direct visualization of diverticula
  • Can identify bleeding sources
  • Allows tissue sampling if needed
  • Screens for colon cancer
• CT scan: Preferred for acute symptoms
  • Shows diverticula and wall thickening
  • Identifies complications (abscess, perforation)
  • CT colonography as alternative to colonoscopy
• Barium enema: Less commonly used
  • Shows diverticula as outpouchings
  • Evaluates extent of disease
  • Not used during acute inflammation
• Flexible sigmoidoscopy: Limited examination of left colon

Laboratory Tests

• Complete blood count: Check for anemia or elevated white cells
• C-reactive protein: Elevated with inflammation
• Stool tests: Rule out infection or inflammatory bowel disease
• Urinalysis: If bladder symptoms present

Differential Diagnosis

Conditions that may present similarly include:

• Irritable bowel syndrome (IBS)
• Inflammatory bowel disease (Crohn's, ulcerative colitis)
• Colorectal cancer
• Ischemic colitis
• Infectious colitis
• Gynecological conditions in women

Treatment Options

Treatment for diverticulosis focuses on preventing symptoms and complications. The approach varies based on whether the condition is asymptomatic, symptomatic, or complicated by diverticulitis or bleeding.

Dietary Management

• High-fiber diet: Cornerstone of treatment
  • Goal: 25-35 grams of fiber daily
  • Gradual increase to avoid gas and bloating
  • Soluble fiber: oats, beans, apples, citrus fruits
  • Insoluble fiber: whole grains, vegetables, wheat bran
• Adequate hydration: 8-10 glasses of water daily
• Foods to emphasize:
  • Fruits and vegetables
  • Whole grains
  • Legumes and beans
  • Nuts and seeds (no longer restricted)
• Foods to limit: Red meat, processed foods, refined grains

Medications

• Fiber supplements:
  • Psyllium (Metamucil)
  • Methylcellulose (Citrucel)
  • Wheat dextrin (Benefiber)
• Probiotics: May help maintain gut health
• Antispasmodics: For cramping (dicyclomine, hyoscyamine)
• Pain management: Acetaminophen preferred over NSAIDs
• Antibiotics: Only for diverticulitis, not uncomplicated diverticulosis
• Mesalamine: Sometimes used for symptomatic disease

Lifestyle Modifications

• Regular exercise: 30 minutes daily, improves bowel function
• Weight management: Reduce abdominal pressure
• Smoking cessation: Reduces complication risk
• Stress management: May help with symptoms
• Bowel habits: Avoid straining, respond to urges promptly
• Limit NSAIDs: Use alternatives when possible

Management of Complications

• Diverticular bleeding:
  • Usually stops spontaneously
  • May require colonoscopy with treatment
  • Angiography with embolization for severe bleeding
  • Surgery if bleeding persists
• Acute diverticulitis:
  • Antibiotics (oral or IV)
  • Clear liquid diet initially
  • Pain management
  • Hospitalization for severe cases

Surgical Treatment

Surgery is reserved for complications or recurrent episodes:

• Elective surgery: After multiple episodes of diverticulitis
• Emergency surgery: For perforation, obstruction, or uncontrolled bleeding
• Types of surgery:
  • Sigmoid colectomy (most common)
  • Primary anastomosis vs. colostomy
  • Laparoscopic vs. open approach

Prevention

While age-related changes cannot be prevented, many lifestyle modifications can reduce the risk of developing diverticulosis or prevent complications in those who already have the condition:

• Dietary prevention:
  • Maintain high-fiber diet from young age
  • Eat plenty of fruits and vegetables
  • Choose whole grains over refined
  • Stay well-hydrated
  • Limit red meat consumption
• Exercise regularly:
  • Aim for 150 minutes moderate activity weekly
  • Include activities that promote bowel motility
  • Yoga and stretching may help
• Maintain healthy weight: Reduce abdominal pressure
• Avoid smoking: Quit if currently smoking
• Manage constipation:
  • Respond promptly to bowel urges
  • Avoid straining
  • Consider squatting position
• Limit certain medications:
  • Use NSAIDs sparingly
  • Discuss alternatives with doctor
• Regular screening: Colonoscopy as recommended by age
• Stress management: May improve gut health
• Probiotic foods: Yogurt, kefir, fermented vegetables

When to See a Doctor

While diverticulosis often requires no treatment, certain symptoms warrant medical evaluation:

• Persistent lower abdominal pain
• Blood in stool or rectal bleeding
• Change in bowel habits lasting more than a few days
• Unexplained weight loss
• Persistent nausea or vomiting
• Fever with abdominal pain
• Severe constipation or inability to pass gas
• Black, tarry stools (melena)

Seek emergency care for:

• Severe, sudden abdominal pain
• High fever (over 101°F/38.3°C) with abdominal pain
• Heavy rectal bleeding
• Signs of shock (rapid pulse, dizziness, cold sweats)
• Rigid, tender abdomen
• Persistent vomiting with inability to keep fluids down

Related Conditions

Frequently Asked Questions

References

1. Strate LL, Morris AM. Epidemiology, Pathophysiology, and Treatment of Diverticulitis. Gastroenterology. 2019;156(5):1282-1298.
2. Peery AF, et al. AGA Clinical Practice Update on Medical Management of Colonic Diverticulitis. Gastroenterology. 2021;160(3):906-911.
3. Tursi A, et al. Colonic diverticular disease. Nat Rev Dis Primers. 2020;6(1):20.
4. Shahedi K, et al. Long-term risk of acute diverticulitis among patients with incidental diverticulosis. Clin Gastroenterol Hepatol. 2013;11(12):1609-1613.
5. Carabotti M, et al. Role of Fiber in Symptomatic Uncomplicated Diverticular Disease: A Systematic Review. Nutrients. 2017;9(2):161.