Irritable Bowel Syndrome II: Clinical Features and Diagnostic Evaluation

The main clinical feature of irritable bowel syndrome, or IBS, is disrupted bowel patterns, categorized into subtypes based on predominant symptoms such as constipation, referred to as IBS-C, diarrhea classified as IBS-D, a combination of both called mixed type is indicated as IBS-M and IBS-U, categorized as unclassified for those not fitting into other categories.

Associated symptoms include lower abdominal distention, bloating, nausea, flatulence, urgency, mucus in the stool, discomfort often relieved by passing stools, and a sensation of incomplete evacuation.

Diagnosing IBS involves a comprehensive history collection, including symptoms, psychosocial factors, family history, and relevant drug and dietary patterns.

Additionally, a physical examination using the Rome IV criteria is required.

The criteria include abdominal pain at least once a week during the last three months, associated with two or more features, such as abdominal pain related to defecation, abdominal pain with altered stool frequency, and abdominal pain with altered stool appearance.

Additional diagnostic tests may include blood tests, stool studies, X-rays, abdominal scans, and endoscopic procedures like colonoscopy.