Crohn’s Disease – Causes, Symptoms, Treatments

What is Crohn’s Disease?

Crohn’s disease is a chronic inflammatory bowel disease (IBD) that causes inflammation of your digestive tract. Unlike ulcerative colitis, which only affects the inner lining of the large intestine (colon), Crohn’s disease can involve the entire thickness of your digestive tract lining, from mouth to anus. 

Complications of Crohn’s Disease

The hallmark feature of Crohn’s disease is inflammation of the digestive tract lining. This inflammation can affect the entire thickness of the bowel wall, from the inner lining to the outer layers. The inflamed tissue in Crohn’s disease can develop ulcers, which are open sores that form on the inner lining of the digestive tract.

Chronic inflammation can cause scar tissue to form in the bowel wall. Over time, this scar tissue can narrow the passageway in the intestines, leading to blockages (strictures). In some cases, inflammation can extend through the bowel wall and create abnormal connections (fistulas) between different parts of the intestines, or from the intestine to other organs in the abdomen, such as the bladder or vagina.

This inflammation and diarrhea can interfere with the body’s ability to absorb nutrients from food, which can also lead to malnutrition. Nutrient absorption can be affected due to inflammation and potential bowel resection surgery. Calcium and vitamin D are crucial for bone health. Deficiencies in these nutrients, often seen in Crohn’s disease, can significantly weaken bones.

This may also disrupt the normal balance between bone formation and breakdown. The body releases inflammatory proteins called cytokines, which can interfere with the activity of osteoblasts (bone-building cells) and promote the activity of osteoclasts (bone-absorbing cells), leading to an overall loss of bone mass.

Calcium is the primary mineral component of bone. Insufficient calcium intake or impaired absorption due to Crohn’s disease limits the availability of materials for building and maintaining strong bones. 

Vitamin D plays a vital role in calcium absorption from the intestines. Deficiency due to Crohn’s disease can hinder the body’s ability to utilize calcium effectively for bone health.

People with Crohn’s disease, especially those with long-standing involvement of the colon, have an increased risk of developing colorectal cancer compared to the general population. There are a couple of reasons for this. The hallmark feature of Crohn’s disease is inflammation of the digestive tract lining. This chronic inflammation can damage and irritate the cells in the colon, increasing their risk of developing abnormal changes over time.

Chronic inflammation can lead to dysplasia, a condition where precancerous changes occur in the cells lining the colon. If left undetected and untreated, these precancerous cells can progress into colon cancer.

The risk of colon cancer is particularly higher in individuals with:

• Extensive disease: Crohn’s disease that affects a larger portion of the colon carries a greater risk than just involving the terminal end (ileum) near the small intestine.
• Longstanding disease duration: The longer someone has Crohn’s disease, especially with colonic involvement, the higher the risk of developing cancer. Studies suggest a risk increase after 8-10 years of disease.

Crohn’s disease is considered a chronic condition. This means it’s a long-term illness that cannot be cured, but its symptoms can be managed. Crohn’s disease is characterized by a relapsing-remitting course, which means periods of flare-ups (when symptoms worsen) alternate with periods of remission (when symptoms improve or disappear completely).

The exact predictability and duration of these cycles can vary greatly between individuals. Some people may experience frequent flare-ups, while others may have longer stretches of remission. There’s no way to predict for sure how Crohn’s disease will progress in any one person.

During remission, inflammation in the digestive tract subsides, and most or all symptoms disappear. People in remission may feel healthy and be able to go about their normal activities. However, it’s important to remember that Crohn’s disease is still present even during remission, and there’s a risk of flare-ups occurring at any time.

Flare-ups occur when inflammation in the digestive tract returns. Symptoms may worsen gradually or come on suddenly. The severity of flare-ups can also vary considerably. Some flare-ups may be mild and only cause minor changes in bowel habits, while others can be severe and debilitating.

Symptoms of Crohn’s Disease

Crohn’s disease can cause a variety of symptoms, and their intensity can vary depending on the severity of inflammation and where it’s located in the digestive tract. 

Digestive symptoms:

• Diarrhea: This is a common symptom, and diarrhea may be bloody in some cases.
• Abdominal pain and cramping: This pain is often felt in the lower right part of the abdomen.
• Urgent need to have a bowel movement (urgency): This means having a sudden and strong urge to use the bathroom.
• Feeling like you haven’t completely emptied your bowels (incomplete evacuation): This can be a very uncomfortable feeling.

General symptoms:

• Fatigue: This extreme tiredness can make it difficult to carry out daily activities.
• Weight loss: This can happen due to decreased appetite, inflammation, or difficulty absorbing nutrients.
• Loss of appetite: This can be caused by inflammation or pain.
• Fever: This can be a sign of infection or inflammation.

Other possible symptoms:

• Mouth ulcers: These can be painful sores on the inside of your mouth or on your lips.
• Joint pain: This can affect any joint in the body, but the knees, ankles, and hips are most commonly affected.
• Eye problems: This can include redness, pain, or vision changes.
• Skin problems: This can include rashes, bumps, or sores.

Causes and Risk Factors of Crohn’s Disease

Crohn’s disease is a complex condition, and the exact cause remains unknown. However, researchers believe a combination of factors likely contributes to its development. Here’s a breakdown of the three main categories:

1. Genetic Factors:
   • Family history: Having a close relative (parent, sibling, or child) with Crohn’s disease significantly increases your risk. While the specific genes haven’t been pinpointed definitively, certain gene variations make you more susceptible.
2. Environmental Factors:
   • Smoking: This is a major risk factor for both developing Crohn’s and experiencing flare-ups. The reason isn’t fully understood, but smoking may alter gut bacteria or immune function.
   • Diet: While diet doesn’t directly cause Crohn’s, certain foods may trigger flare-ups in some people. Common triggers include dairy products, fatty or spicy foods, and artificial sweeteners.
   • Microbiome: The balance of bacteria in your gut (microbiome) may play a role. Disruptions in the gut microbiome composition might contribute to inflammation.
3. Immune System Dysfunction:
   • Abnormal immune response: In Crohn’s disease, the immune system mistakenly attacks healthy tissues in the digestive tract. While the exact trigger for this remains unclear, it’s believed to be influenced by genetics and environmental factors.

Specific factors that might increase risk:

• Family history: As mentioned earlier, having a close relative with Crohn’s disease is a significant risk factor.
• Smoking: Smoking significantly increases your risk of developing Crohn’s disease.
• Certain medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen, as well as some antibiotics and oral contraceptives, may slightly elevate your risk.

How is Crohn’s Disease Diagnosed?

Diagnosing Crohn’s disease typically involves a multi-step process to assess symptoms, rule out other conditions, and identify inflammation in the digestive tract. 

Your doctor will first discuss your medical history in detail, including your current symptoms, past illnesses, family history, and medications you’re taking. A physical examination will be performed to assess for signs of tenderness, swelling, or masses in the abdomen.

Blood tests are another standard diagnosis tool and can be used to check for anemia, which can be caused by blood loss in the digestive tract. Their findings will also be used to evaluate inflammation by measuring levels of C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) and are used to rule out other conditions with similar symptoms.

Stool tests are another staple and are typically used to check for hidden blood in the stool, which can be a sign of inflammation or ulcers, and rule out infections caused by bacteria, parasites, or viruses.

Another diagnostic tool a doctor may employ are imaging tests. These can help visualize the digestive tract and identify abnormalities. Some commonly used options include:

• X-rays: Upper GI series with a barium swallow can reveal blockages or narrowing of the intestines.
• Computed Tomography (CT) Scan: A CT scan can provide detailed cross-sectional images of the abdomen and pelvis to identify inflammation, strictures, or fistulas.
• Magnetic Resonance Imaging (MRI): MRI scans, particularly MR enterography, can be helpful in evaluating the small intestine and identifying inflammation or complications.

Endoscopy allows direct visualization of the inner lining of the digestive tract. These procedures are often the most accurate method for diagnosing Crohn’s disease. Two main types are used:

• Colonoscopy: A flexible tube with a light and camera is inserted through the anus to examine the rectum and colon. Biopsy samples can also be taken during a colonoscopy for further analysis.
• Capsule Endoscopy: A small capsule containing a camera is swallowed and travels through the digestive tract, capturing images of the small intestine. This may be preferred if colonoscopy doesn’t reveal the source of bleeding or inflammation.

How is Crohn’s Disease Treated?

Crohn’s disease has no cure, but treatment focuses on achieving several primary objectives. Chief among those is to reduce Inflammation. The aim is to control the abnormal immune response that triggers inflammation in the digestive tract.

Additionally strategies are employed to induce and maintain remission, with the goal to achieve periods with minimal to no symptoms and improve quality of life. Treatment strategies aim to minimize the frequency and severity of flare-ups and prevent complications. Chronic inflammation can lead to complications like strictures, fistulas, and malnutrition. Treatment helps prevent these and maintain a healthy digestive system.

Medications:

• Corticosteroids: These medications effectively reduce inflammation but are typically used short-term due to potential side effects with long-term use.
• Immunomodulators: These drugs suppress the immune system’s response and help maintain remission. Examples include azathioprine (Imuran) and mercaptopurine (Purinethol).
• Biologics: These newer medications target specific molecules involved in the inflammatory process. Examples include adalimumab (Humira), infliximab (Remicade), and vedolizumab (Entyvio).

Dietary Changes:

• Identifying and avoiding food triggers that worsen symptoms can be helpful for some people.
• A balanced diet rich in fruits, vegetables, and whole grains ensures proper nutrition.
• Nutritional counseling can be beneficial to address deficiencies and optimize nutrient intake.

Lifestyle Modifications:

• Smoking cessation: Smoking significantly worsens disease course and increases the risk of complications. Quitting smoking is essential for managing Crohn’s disease.
• Stress Management: While stress doesn’t directly cause flare-ups, it can worsen symptoms. Stress management techniques like yoga or meditation may be helpful.
• Adequate Sleep: Getting enough sleep is crucial for overall health and may help regulate the immune system.

Surgery:

• Surgery may be necessary in some cases to address complications like:
  • Strictures: Surgery can remove narrowed sections of the intestine to relieve blockages.
  • Fistulas: Surgery can close abnormal connections between the intestine and other organs.
  • Severe Ulcerative Disease: In rare cases, the entire colon may need to be removed (colectomy) with an ileostomy created.

What medications are most often prescribed for Crohn’s Disease?

There isn’t one single medication that’s universally prescribed for Crohn’s disease. The specific medications used will depend on factors like disease severity, location of inflammation, and individual response to treatments. However, several medication classes are commonly used to manage Crohn’s disease.

• Aminosalicylates (5-ASA): These medications are typically used for mild to moderate Crohn’s disease, particularly affecting the colon. Examples include sulfasalazine (Azulfidine), mesalamine (Asacol, Lialda), olsalazine (Dipentum), and balsalazide (Disulfusal). They work by reducing inflammation in the digestive tract lining.
• Corticosteroids:  These powerful medications effectively reduce inflammation but are typically used short-term due to potential side effects with long-term use. Examples include prednisone and methylprednisolone. They are often used to induce remission during a flare-up.
• Immunomodulators:  These drugs suppress the immune system’s response and help maintain remission after corticosteroids have brought inflammation under control. Examples include azathioprine (Imuran) and mercaptopurine (Purinethol). They take weeks or months to take full effect.
• Biologics: These newer medications target specific molecules involved in the inflammatory process. They are typically used for moderate to severe Crohn’s disease or when other medications haven’t been effective. Examples include adalimumab (Humira), infliximab (Remicade), vedolizumab (Entyvio), and ustekinumab (Stelara). Biologics can be administered by injection or infusion.
• Antibiotics: These medications are used to treat infections that may arise due to Crohn’s disease, such as abscesses or fistulas. Examples include metronidazole (Flagyl), ciprofloxacin (Cipro), and rifaximin (Xifaxan).