What Is IBS?

Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by recurrent abdominal pain associated with changes in bowel habits. It is a “functional” disorder, defined by the presence of symptoms without visible signs of damage or disease in the digestive tract. This doesn’t mean your symptoms are any less real! IBS can be debilitating, and numerous treatments have emerged to address diarrhea, constipation, and pain.

IBS is categorized into subtypes based on predominant stool pattern: diarrhea‑predominant (IBS‑D), constipation‑predominant (IBS‑C), mixed (IBS‑M), or unclassified.

Symptoms

• Abdominal pain or cramping, often relieved or worsened after bowel movements.
• Diarrhea, constipation, or alternating between the two.
• A sensation of incomplete bowel movements.
• Bloating or excess gas.

Causes and Triggers

• The exact cause of IBS is unknown; factors may include gut motility problems, heightened pain sensitivity, and imbalances in gut bacteria.
• Post‑infectious changes after a gastrointestinal infection.
• Stress and emotional factors can exacerbate symptoms.
• Certain foods (high FODMAPs, dairy, caffeine, artificial sweeteners) can trigger or worsen symptoms.

Diagnosis

• IBS is diagnosed based on symptom criteria (such as Rome IV) and the exclusion of other conditions.
• Your provider may order blood tests, stool tests, or endoscopic procedures to rule out inflammatory bowel disease, celiac disease, or other disorders.
• No single test confirms IBS; a comprehensive evaluation is essential.

Management

• Dietary changes: Increasing soluble fiber for IBS‑C and avoiding trigger foods including those identified from a low-FODMAP diet.

Important: Sometimes patients develop avoidant/restrictive food intake disorder (ARFID) in response to fear of triggering symptoms.  It is also important for patients to try and differentiate consistent trigger foods from foods that once or twice happened to be eaten around the time of a bout of discomfort.  Continue eating a wide variety of foods for adequate nutrition.

• Medications: Psyllium husk, antidiarrheal agents, laxatives, or prescription medications such as rifaximin, eluxadoline, lubiprostone, or linaclotide based on your subtype, and neuromodulators and antispasmodics for pain
• Behavioral therapies: Stress reduction techniques, cognitive behavioral therapy, and regular exercise can help manage symptoms.

The first step to treating IBS is to ensure the correct diagnosis, so patients can proceed with the confidence that there isn’t anything else dangerous or progressive underlying their symptoms.  IBS is a chronic condition, but with a tailored treatment plan, many patients achieve good symptom control and maintain a high quality of life.