Crohn's Disease: Symptoms, Causes & Treatment

Crohn's disease is a chronic inflammatory condition that can affect any part of the digestive tract from the mouth to the anus, but most commonly affects the end of the small intestine (ileum) and the beginning of the colon. The disease is characterized by deep, patchy inflammation in the walls of the digestive tract, meaning inflamed areas alternate with healthy tissue. It is classified as one of the inflammatory bowel diseases (IBD) alongside ulcerative colitis.

The exact cause remains unclear, but it is believed to result from an abnormal immune response to beneficial gut bacteria, driven by genetic and environmental factors. Crohn's disease affects approximately 1 in 500 people worldwide and is more common in industrialized countries. In the Middle East and Jordan, there has been a gradual increase in diagnostic rates over the past two decades. The disease can affect people of any age but typically begins before age 30.

Crohn's disease significantly impacts quality of life, causing debilitating symptoms such as chronic diarrhea, abdominal pain, and fatigue, along with serious complications that may require surgery. Treatment focuses on suppressing inflammation, controlling symptoms, and achieving periods of remission (low disease activity), which substantially improves quality of life.

Crohn's disease symptoms vary depending on the location and severity of inflammation, developing gradually over weeks or months. Some patients experience mild symptoms, while others suffer from severe, debilitating ones. Symptoms often fluctuate between periods of remission (low activity) and flare-ups (active inflammation). Women may experience worse symptoms during menstruation.

• Chronic diarrhea: May be watery, contain blood or mucus, occurring multiple times daily.
• Abdominal pain and cramping: Often around the navel or lower abdomen, worsened after eating.
• Weight loss: Due to malabsorption, chronic diarrhea, and decreased appetite.
• Loss of appetite: Patient may feel full quickly or have no desire to eat.
• Fatigue and weakness: Caused by nutrient, vitamin deficiency, and anemia.
• Fever: May occur during active disease phases due to inflammation.
• Delayed puberty and growth: In children, may affect development due to malnutrition.
• Mouth ulcers: Painful sores inside the mouth may develop.
• Rectal pain or bleeding: Anal bleeding or pain during bowel movements may occur.
• Pain around the anus: May result from fistulas or anal fissures.
• Extraintestinal symptoms: May include joint pain, eye redness, rash, or oral thrush.
• Exhaustion and depression: Chronic disease may affect mental and emotional health.

• Genetic factors: Family history increases risk by 15-20%, with over 240 genetic variants associated with the disease.
• Abnormal immune response: The immune system mistakenly attacks the intestinal lining and beneficial bacteria, causing chronic inflammation.
• Intestinal barrier defect: A weakened protective intestinal layer allows bacteria and harmful substances to penetrate the intestinal walls.
• Bacteria and viruses: Certain infections may trigger excessive immune response, particularly in genetically predisposed individuals.
• Environmental factors: Pollution, high-fat processed diet, and psychological stress may increase disease risk.
• Smoking: A major environmental factor strongly associated with disease and symptom severity.
• Medications: Antibiotics may alter gut bacteria composition, increasing disease risk.
• Dysbiosis: Reduced bacterial diversity in the gut may contribute to disease development.

• Age: Usually starts between 15-35 years, though can occur at any age.
• Family history: Having a parent or sibling with the disease significantly increases risk.
• Ethnicity: People of European and Ashkenazi Jewish descent have higher incidence rates.
• Active and passive smoking: Major modifiable risk factor; smokers experience worse disease course.
• Stress and depression: Psychological stress may worsen symptoms and intestinal inflammation.
• Diet: High fat and processed foods with low fiber increase disease risk.
• Obesity: Being overweight may elevate systemic inflammation markers.
• NSAIDs: Pain relievers like ibuprofen may increase disease risk.
• Oral contraceptives: May slightly increase disease risk in women.
• Urban living conditions: Industrialized urban areas with pollution show higher incidence rates.

Crohn's disease diagnosis is based on a combination of clinical examination, laboratory tests, and imaging studies, as no single test confirms diagnosis. The physician typically begins with a detailed medical history followed by a thorough physical examination.

• Physical examination: Abdominal palpation to check for pain and bloating, rectal examination to assess for bleeding or fistulas.
• Stool tests: To exclude bacterial or parasitic infections; measure inflammatory markers such as fecal calprotectin (>50-100 mcg/g indicates inflammation).
• Blood tests: Complete blood count (CBC) for anemia (hemoglobin <12 g/dL in women), liver and kidney function tests, C-reactive protein (CRP >10 mg/L), and iron, folate, and vitamin B12 levels.
• Colonoscopy: Allows visualization of the colon and terminal ileum with tissue biopsy (Biopsy) for confirmation. Shows deep, often patchy ulcers.
• Upper endoscopy: To examine the esophagus and stomach if symptoms suggest involvement.
• Magnetic resonance imaging (MRI): Preferred for assessing inflammation and fistulas without radiation exposure.
• Ultrasound: Can measure bowel wall thickness (>3 mm suggests inflammation).
• CT scan: Useful for detecting complications such as abscesses or fibrosis.
• X-rays: May be used in emergencies to assess for bowel perforation.

Medications

• TNF Inhibitors: Such as infliximab and adalimumab, suppress TNF inflammatory protein and are used for moderate to severe disease. May take 4-8 weeks to show effect.
• Integrin Inhibitors: Such as vedolizumab, reduce immune cell movement to the intestines.
• JAK Inhibitors: Such as upadacitinib, a new class of biologic drugs.
• Corticosteroids: Such as prednisone, used for acute flares to speed symptom improvement, but not for long-term maintenance due to side effects.
• Mesalamine (5-ASA): Such as sulfasalazine and mesalamine, reduce inflammation in the colon and ileum, effective for mild disease.
• Immunosuppressants: Such as azathioprine and mercaptopurine, used for steroid-resistant cases.
• Antibiotics: Such as ciprofloxacin and metronidazole, may help treat complicated cases with fistulas or infections.
• Nutritional supplements: Such as vitamin B12, folic acid, iron, calcium, and vitamin D to correct deficiencies.

Procedures and Surgery

• Surgery: May be necessary in 70-80% of Crohn's patients over their lifetime. Used when medical therapy fails or complications occur such as obstruction, fistula, or abscess. Involves removal of the inflamed bowel segment (resection) and may affect nutrient absorption.
• Elemental Diet: In some cases, particularly in children, complete liquid nutrition may help achieve remission and rest the intestines.
• Endoscopic Procedures: May be used to dilate narrow areas (dilation) or treat fistulas.

Lifestyle and Dietary Changes

• Appropriate diet: Avoid trigger foods (usually fatty foods, spices, and high fiber during active disease). Eat small, frequent meals. A low FODMAP diet may be beneficial.
• Smoking cessation: One of the most important modifications as it significantly worsens disease severity.
• Stress management: Techniques like yoga, meditation, and psychotherapy may reduce symptom flares.
• Regular exercise: Light to moderate exercise may improve overall and mental health.
• Proper hydration: Drink adequate water to replace fluid lost from diarrhea.
• Adequate sleep: Poor sleep may increase inflammation and symptoms.
• Periodic nutritionist consultation: May help develop a personalized dietary plan.

• Bowel Obstruction: May occur due to scarring and strictures, causing severe bloating, pain, and constipation. May require emergency surgery.
• Fistula: Abnormal tunnels forming between bowel segments or between bowel and other organs or skin, potentially causing serious infections.
• Abscess: Painful pus collection inside or around the intestines, requiring drainage or surgery.
• Severe intestinal bleeding: Heavy bleeding may lead to severe anemia and may require blood transfusion or surgery.
• Malnutrition and anemia: Malabsorption causes deficiency in iron and vitamins, especially B12 and folate, leading to anemia and weakness.
• Arthritis and osteoporosis: Joint inflammation may occur; disease and corticosteroid medications may cause bone loss.
• Liver disease: Primary sclerosing cholangitis or liver cirrhosis may occur rarely.
• Cancer: Patients have slightly higher risk of colorectal cancer, especially with long-standing disease and chronic inflammation.
• Blood clots (Thromboembolism): Increased risk of venous and arterial thrombosis due to inflammation.
• Psychological complications: Depression and anxiety are very common due to chronic disease impact on quality of life.

• Avoid smoking and secondhand smoke: Quitting or never starting smoking is the most important preventive measure for at-risk individuals.
• Follow a healthy, balanced diet: Focus on whole foods, vegetables, fruits, and reduce fats and processed foods to lower risk.
• Manage psychological stress: Practice relaxation and mindfulness techniques to reduce inflammation and symptoms.
• Maintain healthy weight: Obesity increases inflammation; maintaining ideal weight is important.
• Exercise regularly: Moderate physical activity improves digestive and overall health.
• Limit antibiotic and NSAID use: Use these medications only when truly necessary.
• Get adequate sleep: Good sleep boosts immune function and reduces inflammation.
• Regular screening for those with family history: May aid early diagnosis if disease develops.
• Prevent infections: Maintain personal and food hygiene to reduce infections that might trigger disease.
• Consume probiotic-rich foods: Fermented dairy and fermented foods may help maintain gut bacterial balance.