Irritable bowel syndrome (IBS) is a common "label" people use to describe a wide range of clinical symptoms related to diarrhea, constipation, cramps, abdominal pain, gas, and bloating. There are strict criteria (Rome IV criteria) that are used to define IBS. However, IBS as a diagnosis is used much more loosely by a patient and even their doctors that involves a careful history and physical examination.
There are 3 different forms of IBS:
Diarrhea-predominant (D-IBS) involves abdominal discomfort or pain, urgency, and diarrhea.
Constipation-predominant (C-IBS) involves abdominal discomfort or pain, bloating, and constipation.
Alternating constipation and diarrhea (A-IBS) involve both.
"There are 3 different forms of IBS: Diarrhea-predominant (D-IBS), constipation-predominant (C-IBS), and alternating constipation and diarrhea (A-IBS)."
IBS is the most prevalent functional gastrointestinal disorder. It affects approximately 14%
of the global population. There is a significant economic impact on the health care system from it as many days of work are missed because of it and because IBS greatly reduces patients’ quality of life.
Symptoms of IBS are some of the most common reasons why patients are referred to gastroenterologists.
The precise cause of IBS remains unknown. "Unknown" implies that it involves a variety of factors, such as infection, inflammation, medication, and stress, in a genetically predisposed individual.
"The precise cause of IBS remains unknown."
Treating IBS symptoms can be challenging. There is no one medication that "cures" the disorder. Treatment focuses on improving symptoms and quality of life. Diet has a major role.
Many patients report that symptoms are triggered by food. Food ingestion may produce heightened symptoms of IBS. Dietary interventions can improve IBS symptoms. This is the most reasonable initial and ongoing treatment approach.
However, the role of diets for the treatment of IBS symptoms is complex and poorly defined. Clinical studies have been limited by various factors.
"Many patients report that symptoms are triggered by food."
"However, the role of diets for the treatment of IBS symptoms is complex and poorly defined."
Cheap and effective testing for food intolerance is lacking. Avoid the expensive and unproven commercial food-specific allergy testing.
Specific dietary IBS triggers are likely very common. The best initial management of IBS with dietary adjustment involves either a single-food elimination diet for some common triggers. These are lactose and fructose.
A common elimination diet (eg, low-FODMAP) is usually recommended. After starting a low-FODMAP diet you can aim for targeted reintroduction after 4 weeks, under the guidance of a registered dietitian.
Future larger studies are needed to better define the efficacy of specific dietary options for IBS patients.
FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) are short-chain carbohydrates with limited (or minimal) small intestine absorption. This leads to hydrogen and methane production in the intestines, probable changes in gut flora, altering of colonic epithelial function, and may also cause local inflammation. These changes can significantly heighten gastrointestinal symptoms in patients with IBS, with excessive gas, bloating, and loose stools.
I will blog more on the low-FODMAP diet in the near future.