Irritable bowel syndrome (IBS) was first discovered in the late 1800s by a Canadian physician, Sir William Osler, who coined the term mucus colitis to describe the condition involving abdominal pain and passing of mucus in the stool.

IBS is a group of symptoms including abdominal pain and changes in bowel movements, such as diarrhea, constipation, or a combination of both, and it often persists throughout life without increasing the risk of bowel cancer.

IBS affects about one in 10 people worldwide, with 10 to 15% of the North American population estimated to have it, and it is more prevalent in women than men and less common in people over 50.

Classic IBS symptoms include abdominal pain, discomfort, cramps, bloating, and incomplete bowel evacuation, and the diagnosis is based on fulfilling specific pattern-based criteria known as the Rome criteria, which include recurrent abdominal pain and specific changes related to bowel movements.

The Rome 4 criteria for diagnosing IBS require recurrent abdominal pain at least one day per week in the last three months, along with at least two specific changes related to bowel movements, and there are four types of IBS: IBSD (diarrhea), IBSC (constipation), IBSM (mixed), and IBSU (unclassified).

Red flag symptoms, such as unexplained weight loss, anemia, blood in the stool, nighttime diarrhea, and intensifying abdominal pain, indicate the need for further investigation beyond IBS.

Possible alternatives to IBS include chronic infections like C. diff or Giardia, celiac disease, food intolerances, small intestine bacterial overgrowth, and inflammatory bowel diseases like ulcerative colitis and Crohn's disease.

IBS can manifest as constipation, and stress has been linked to the onset and improvement of symptoms, with patients reporting increased levels of anxiety, depression, and phobias.

A recent study found that people with IBS were more likely to have anxiety and suggested that repeated use of antibiotics during childhood might increase the risk of IBS and anxiety by altering normal gut bacteria, influencing nerve cell development and mood.

Treatment for IBS is individualized, but some general recommendations include cutting out caffeine, alcohol, and spicy and fatty foods to see improvement in symptoms.

The low FODMAP diet involves temporarily reducing or eliminating foods that the small intestine struggles to absorb, such as milk, ice cream, wheat, beans, lentils, onions, apples, and garlic.

Alternative treatments for IBS include acupuncture, mindfulness, and Cognitive Behavioral Therapy (CBT), in addition to medications that are repurposed from treating depression.

For individuals not finding relief from dietary changes and treatments, focusing on supporting the gut microbiome, considering alternative diagnoses, and addressing the brain-gut connection may be beneficial.

While stress and anxiety play a role in IBS, the condition is not solely psychological, and a comprehensive approach involving dietary modification, medication, and alternative therapies is recommended for managing symptoms and improving quality of life.