Irritable bowel syndrome

Overview

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder that affects the large intestine (colon). It is characterized by a group of symptoms that include abdominal pain, bloating, and changes in bowel habits such as diarrhea, constipation, or both. IBS is a chronic condition that does not cause structural damage or increase the risk of serious disease, but it can significantly impact a person's quality of life. It affects individuals of all ages but is more prevalent in women and people under the age of 50.

Causes

The exact cause of irritable bowel syndrome is unknown, but several factors are believed to contribute to its development:

• Abnormal gut motility: Irregular contractions of the intestinal muscles can lead to diarrhea or constipation.

• Increased gut sensitivity: Enhanced sensitivity in the intestines may cause pain or discomfort from normal digestive processes.

• Brain-gut interaction: Disrupted communication between the brain and the gastrointestinal tract can affect digestion and stress response.

• Infections: A history of severe gastrointestinal infection or food poisoning may trigger IBS in some people.

• Changes in gut microbiota: Alterations in the balance of intestinal bacteria may play a role in symptom development.

• Stress and mental health: Anxiety, depression, and other psychological conditions are closely linked to IBS symptoms.

Symptoms

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

• Abdominal pain or cramping: Often relieved by a bowel movement.

• Bloating and gas

• Diarrhea (IBS-D): Frequent loose stools, often urgent or explosive.

• Constipation (IBS-C): Infrequent, hard, or difficult-to-pass stools.

• Mixed bowel habits (IBS-M): Alternating between diarrhea and constipation.

• Mucus in the stool

IBS symptoms may be triggered or worsened by certain foods, stress, hormonal changes, or gastrointestinal infections.

Diagnosis

IBS is diagnosed based on symptoms and by ruling out other conditions. The diagnostic process includes:

• Medical history and symptom evaluation: Using criteria such as the Rome IV diagnostic criteria (recurrent abdominal pain at least 1 day/week in the last 3 months, associated with defecation, change in stool frequency, or form).

• Physical examination: To identify tenderness or other signs of gastrointestinal issues.

• Exclusion of other disorders: Tests may be done to rule out celiac disease, inflammatory bowel disease (IBD), infections, or colon cancer.

• Stool tests: To check for infection or blood in stool.

• Blood tests: To check for anemia, inflammation, or celiac disease markers.

• Colonoscopy: Recommended in some cases, especially in individuals over 50 or with alarm symptoms (e.g., weight loss, bleeding, family history of colon cancer).

Treatment

Treatment for irritable bowel syndrome focuses on relieving symptoms and improving quality of life. Options vary based on the subtype (IBS-D, IBS-C, or IBS-M) and severity:

• Dietary modifications:

  • Low FODMAP diet: Avoiding fermentable carbohydrates that trigger symptoms.

  • Increasing fiber (for constipation-predominant IBS).

  • Avoiding caffeine, alcohol, fatty foods, and known personal triggers.

• Medications:

  • Antispasmodics (e.g., hyoscine, dicyclomine) for abdominal cramping.

  • Laxatives for constipation (e.g., polyethylene glycol, lubiprostone).

  • Anti-diarrheal agents (e.g., loperamide) for diarrhea.

  • Serotonin receptor agents (e.g., alosetron for IBS-D, tegaserod for IBS-C).

• Psychological therapies: Cognitive-behavioral therapy (CBT), mindfulness, or hypnotherapy can help manage stress-related symptoms.

• Probiotics: May help balance gut bacteria in some patients.

Prognosis

IBS is a chronic, non-life-threatening condition that tends to fluctuate over time. While it does not lead to serious health consequences such as cancer or permanent damage to the intestines, it can significantly affect quality of life. With appropriate treatment and lifestyle changes, many individuals can manage their symptoms effectively. Long-term success often requires a combination of dietary adjustments, stress management, and ongoing support from healthcare providers.