Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is a common, chronic disorder that affects the large intestine. It is characterized by a group of symptoms that typically occur together, including abdominal pain, cramping, bloating, gas, and changes in bowel habits (diarrhea, constipation, or both). Unlike inflammatory bowel diseases like ulcerative colitis, IBS does not cause inflammation or changes in bowel tissue.

Causes:

The exact cause of IBS is not fully understood, but it is believed to involve a combination of factors related to how the brain and gut work together (the gut-brain axis). Contributing factors may include:

• Muscle contractions in the intestine: The walls of the intestines are lined with layers of muscle that contract to move food through the digestive tract. Contractions that are stronger, last longer, or are weaker than normal can cause symptoms.
• Nervous system abnormalities: Nerves in the gut may be overly sensitive to normal digestive processes, leading to pain, bloating, or discomfort.
• Severe infection: IBS can develop after a severe bout of diarrhea (gastroenteritis) caused by bacteria or a virus (post-infectious IBS).
• Early life stress: People exposed to stressful life events in childhood tend to have more symptoms of IBS.
• Changes in gut microbes (microbiome): Differences in the bacteria, fungi, and viruses in the gut may play a role.
• Food sensitivities: While not true allergies, certain foods can trigger IBS symptoms in some individuals. Common culprits include certain carbohydrates (FODMAPs), dairy, and gluten.
• Stress: While not a cause, stress can significantly worsen IBS symptoms.

Symptoms:

IBS symptoms vary from person to person and can fluctuate over time. Common symptoms include:

• Abdominal pain or cramping: Often relieved by a bowel movement.
• Bloating and gas.
• Changes in bowel habits:
  • IBS-C (constipation-predominant): Hard, lumpy stools; infrequent bowel movements.
  • IBS-D (diarrhea-predominant): Loose, watery stools; frequent bowel movements; urgency.
  • IBS-M (mixed): Alternating periods of constipation and diarrhea.
• Mucus in the stool.
• Feeling of incomplete bowel evacuation.
• Other symptoms (less common but can occur):
  • Fatigue
  • Headache
  • Depression or anxiety
  • Heartburn
  • Urinary frequency or urgency

Diagnosis:

Diagnosing IBS involves ruling out other conditions and identifying a pattern of symptoms. There is no specific test for IBS. Diagnosis is often based on the Rome IV criteria, which include:

• Recurrent abdominal pain: On average, at least one day per week in the last three months, associated with two or more of the following:
  • Related to defecation.
  • Associated with a change in frequency of stool.
  • Associated with a change in form (appearance) of stool.
• Medical history and physical exam: The doctor will ask about your symptoms, bowel habits, diet, stress levels, and family history. A physical exam may be performed.
• Ruling out other conditions: Blood tests (e.g., to check for celiac disease, inflammation markers), stool tests (to rule out infection or inflammation), or in some cases, colonoscopy may be performed, especially if “alarm symptoms” are present (e.g., weight loss, fever, rectal bleeding, anemia, new onset over age 50).

Treatment:

Treatment for IBS focuses on managing symptoms and improving quality of life. It often involves a combination of dietary changes, lifestyle modifications, and medications.

• Dietary Adjustments:
  • Low FODMAP diet: A diet that limits certain types of carbohydrates that can be poorly absorbed and ferment in the gut, causing symptoms. This is often done under the guidance of a dietitian.
  • Fiber supplementation: For IBS-C, increasing soluble fiber (e.g., psyllium) can help.
  • Avoiding trigger foods: Identifying and avoiding personal triggers like caffeine, alcohol, spicy foods, or fatty foods.

• Lifestyle Modifications:
  • Stress management: Techniques such as meditation, yoga, mindfulness, and regular exercise can help reduce stress, which can worsen IBS symptoms.
  • Regular exercise: Can help regulate bowel function and reduce stress.
  • Adequate sleep: Maintaining a consistent sleep schedule.
• Medications:
  • Antidiarrheals: For IBS-D (e.g., loperamide).
  • Laxatives: For IBS-C (e.g., polyethylene glycol).
  • Antispasmodics: To reduce abdominal pain and cramping (e.g., dicyclomine, hyoscyamine).
  • Low-dose antidepressants: Certain antidepressants (e.g., tricyclic antidepressants, SSRIs) can help reduce pain and affect gut motility.
  • Specific IBS medications:
    • Linaclotide, plecanatide, lubiprostone: For IBS-C, to increase fluid in the intestines and promote bowel movements.
    • Rifaximin, eluxadoline: For IBS-D, to target gut bacteria or reduce gut contractions.
• Probiotics: Some individuals find relief with certain probiotic strains, though research is ongoing.
• Psychological therapies:
  • Cognitive Behavioral Therapy (CBT): Helps change thought patterns and behaviors related to IBS.
  • Gut-directed hypnotherapy: Can help regulate gut function and reduce symptoms.

Managing IBS is a personalized process, and what works for one person may not work for another. Working closely with a healthcare provider to find the most effective combination of treatments is key.