Microscopic Colitis vs Diverticulitis: Understanding the Differences

When struggling with chronic digestive symptoms, getting the right diagnosis is crucial. Microscopic colitis and diverticulitis are two inflammatory digestive conditions that can cause similar symptoms but have very different causes, treatments, and long-term implications. As someone who's navigated the complex world of digestive disorders firsthand, I understand the frustration of sorting through confusing medical terminology and overlapping symptoms.

In this comprehensive guide, we'll compare these two conditions side-by-side, so you can better understand your symptoms and have more productive conversations with your healthcare provider.

What Is Microscopic Colitis?

Microscopic colitis is an inflammatory bowel disease that causes chronic watery diarrhea. Despite causing significant inflammation, the colon appears normal during a standard colonoscopy. The inflammation is only visible when colon tissue samples are examined under a microscope (hence the name "microscopic").

There are two main types:

• Lymphocytic colitis: Characterized by increased lymphocytes (white blood cells) in the colon lining
• Collagenous colitis: Distinguished by a thick band of collagen under the colon lining

Both types cause similar symptoms and are often treated the same way.

What Is Diverticulitis?

Diverticulitis is completely different in its underlying mechanism. This condition occurs when small pouches (diverticula) that form in the wall of the colon become infected or inflamed.

These pouches develop when weak spots in the colon wall give way under pressure, creating small bulges. When these pouches become inflamed or infected, the condition is called diverticulitis, which can range from mild to severe.

For a more comprehensive understanding of diverticulitis, check out our complete guide to understanding diverticulitis, which covers everything from basic definitions to management strategies.

Key Differences in Symptoms

While both conditions affect the digestive tract, their symptoms can be quite different:

Microscopic Colitis Symptoms

• Chronic, watery diarrhea (the hallmark symptom)
• Little to no blood in stool
• Mild abdominal cramps
• Weight loss
• Fatigue
• Symptoms may come and go, with episodes lasting weeks to months

Diverticulitis Symptoms

• Severe abdominal pain, usually in the lower left abdomen
• Fever and chills
• Nausea and vomiting
• Constipation or diarrhea
• Bloating and gas
• Sometimes blood in stool (more common with bleeding diverticula)
• Symptoms tend to have a sudden onset during flare-ups

For more detailed information about diverticulitis symptoms, read our article on diverticulitis symptoms: from early warning signs to acute episodes.

Different Causes and Risk Factors

The causes of these conditions are as different as their symptoms:

Microscopic Colitis

The exact cause remains unknown, but several factors may contribute:

• Autoimmune responses
• Medications (especially NSAIDs, PPIs, SSRIs)
• Bacterial or viral infections
• Bile acid malabsorption

Risk factors include:

• Age (most common in people over 50)
• Sex (more common in women)
• Smoking
• Other autoimmune conditions (rheumatoid arthritis, celiac disease)
• Genetic factors

Diverticulitis

Diverticulitis develops when diverticula become infected or inflamed. The formation of diverticula themselves (diverticulosis) is linked to:

• Low-fiber diet
• Increased pressure in the colon
• Weakened intestinal walls
• Irregular bowel movements

Risk factors include:

• Age (risk increases after 40)
• Obesity
• Sedentary lifestyle
• Diet high in processed foods and red meat
• Certain medications

To explore more about what causes diverticulitis flare-ups, visit our detailed article on what causes diverticulitis flare-ups: triggers explained.

Diagnostic Approaches

The diagnostic process for these conditions differs significantly:

Microscopic Colitis Diagnosis

• Colonoscopy with biopsies: The colon appears normal during the procedure, but microscopic examination of tissue samples reveals inflammation
• Medical history review: Particularly medication use
• Blood tests: To rule out other conditions and check for inflammatory markers
• Stool tests: To exclude infectious causes

Diverticulitis Diagnosis

• CT scan: The primary diagnostic tool, showing inflamed diverticula
• Ultrasound: Sometimes used, especially in younger patients or pregnant women
• Blood tests: To check for infection and inflammation
• Stool tests: To rule out other causes
• Colonoscopy: Usually performed after acute inflammation resolves to assess the colon

For a comprehensive overview of the diagnostic process for diverticulitis, check out our article on how is diverticulitis diagnosed? Tests, procedures, and what to expect.

Treatment Approaches

The treatment approaches for these conditions are quite different, reflecting their distinct underlying mechanisms:

Microscopic Colitis Treatment

• Medication changes: Stopping medications that may cause the condition
• Anti-inflammatory medications: Budesonide, a corticosteroid with limited systemic effects
• Anti-diarrheal medications: Loperamide or cholestyramine
• Biologics: In severe cases
• Dietary changes: Eliminating dairy, gluten, or caffeine may help some patients
• Time: Some cases resolve on their own within a few years

Diverticulitis Treatment

• Mild cases:
  • Rest and liquid diet
  • Oral antibiotics
  • Pain management
  • Gradual return to normal diet
• Severe cases:
  • Hospitalization
  • IV antibiotics
  • Possible surgical intervention for complications
• Long-term prevention:
  • High-fiber diet
  • Regular exercise
  • Maintaining healthy weight
  • Staying hydrated

Learn more about treatment options in our home treatment for mild diverticulitis: step-by-step protocol.

Potential Complications

Both conditions can lead to complications if not properly managed:

Microscopic Colitis Complications

• Dehydration
• Malnutrition
• Electrolyte imbalances
• Reduced quality of life
• Rarely becomes severe enough to require surgery

Diverticulitis Complications

• Abscess
• Perforation
• Fistula
• Obstruction
• Peritonitis (a medical emergency)
• Recurrent infections

For an in-depth look at diverticulitis complications, read our article on diverticulitis complications: prevention, recognition, and treatment.

When to See a Doctor

For Microscopic Colitis Symptoms

Seek medical attention if you experience:

• Persistent diarrhea (lasting more than a few days)
• Unexplained weight loss
• Fatigue or weakness
• Dehydration signs (excessive thirst, dry mouth, decreased urination)

For Diverticulitis Symptoms

Seek immediate medical attention if you experience:

• Severe abdominal pain, especially in the lower left abdomen
• Fever above 100.4°F (38°C)
• Inability to keep liquids down
• Persistent vomiting
• Signs of bleeding (blood in stool)
• Severe constipation

Living with These Conditions

Living with Microscopic Colitis

• Plan ahead for outings (know bathroom locations)
• Consider dietary modifications (food diary can help identify triggers)
• Stay well-hydrated
• Manage stress, which can trigger symptoms
• Join support groups for inflammatory bowel conditions

Living with Diverticulitis

• Follow a high-fiber diet between flares
• Stay physically active
• Recognize early warning signs of flares
• Have an emergency plan for flare-ups
• Maintain regular check-ups with your gastroenterologist

For more comprehensive strategies on daily management of diverticulitis, read our guide on living with diverticulitis: a comprehensive guide to daily management.

The Connection Between Inflammatory Conditions

It's worth noting that having one inflammatory bowel condition may increase the risk of developing others. The gut's complex immune system and microbiome play important roles in various digestive conditions. To learn more about connections between different digestive disorders, check out our article on the link between diverticulitis and other digestive disorders.

Key Takeaways

	Microscopic Colitis	Diverticulitis
Primary Symptom	Chronic watery diarrhea	Acute abdominal pain (often left-sided)
Visual Diagnosis	Normal colonoscopy; abnormal biopsies	Abnormalities visible on CT scan
Onset	Gradual	Often sudden
Pain Level	Mild to moderate	Moderate to severe during flares
Treatment Approach	Anti-inflammatories, dietary changes	Antibiotics, possible surgery
Bleeding	Rare	More common
Long-term Management	Medication, diet modification	High-fiber diet, lifestyle changes

Conclusion

Microscopic colitis and diverticulitis are both inflammatory conditions affecting the colon, but they differ significantly in their presentation, diagnosis, and treatment. Understanding these differences is crucial for proper management and improving quality of life.

If you're experiencing digestive symptoms, it's essential to consult with a healthcare professional for an accurate diagnosis. Both conditions are manageable with proper medical care, and many people with these conditions lead full, active lives.

Remember that getting the right diagnosis is the first step toward effective treatment. Don't hesitate to seek a second opinion if your symptoms persist despite treatment, as outlined in our article second opinion for diverticulitis: when and how to seek one.

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References and Additional Resources:

• Mayo Clinic: Microscopic Colitis
• Cleveland Clinic: Diverticular Disease
• National Institute of Diabetes and Digestive and Kidney Diseases: Microscopic Colitis
• American College of Gastroenterology Guidelines for Management of Acute Diverticulitis
• Differences between diverticulosis vs. diverticulitis

This article is based on scientific research and personal experience but should not replace professional medical advice. Always consult with healthcare providers for diagnosis and treatment of medical conditions.

Last updated: March 24, 2025