What is Irritable Bowel Syndrome (IBS)? Understanding Symptoms, Causes, and Treatments

Irritable bowel syndrome (IBS) is a prevalent condition affecting a significant portion of the population, estimated to be over 15 percent. This article aims to provide a comprehensive understanding of What Is Irritable Bowel Syndrome, its symptoms, potential causes, diagnostic approaches, and available treatment options, catering to individuals and families seeking clear and reliable information.

IBS falls under the category of functional gastrointestinal disorders. This means that while standard medical tests may not reveal any structural abnormalities or visible issues, the bowel doesn’t function as it should. You might have heard IBS referred to by older names like spastic colon, spastic colitis, mucous colitis, or nervous stomach. These terms are no longer in common use. It’s crucial to distinguish IBS from Inflammatory Bowel Disease (IBD), which includes conditions like ulcerative colitis and Crohn’s disease. Importantly, the management of IBS is primarily medical, and surgery is not a typical treatment for this condition.

Recognizing the Symptoms of Irritable Bowel Syndrome

Individuals experiencing irritable bowel syndrome often present with a range of symptoms, primarily centered around abdominal pain and alterations in bowel habits. These changes can manifest as diarrhea, constipation, or a fluctuating pattern of both. It’s common for individuals to identify as having either diarrhea-predominant IBS (IBS-D) or constipation-predominant IBS (IBS-C), although symptoms can shift over time. The severity of symptoms varies greatly from person to person, ranging from mild discomfort to significant disruption of daily life. Symptoms can be episodic, appearing and disappearing, and their nature can evolve over time.

The most frequently reported symptoms of what is irritable bowel syndrome include:

Abdominal pain, which is a hallmark symptom
A sensation of fullness
Excessive gas and bloating

In addition to these, other symptoms commonly associated with IBS can include:

Abdominal cramps
Generalized abdominal aches
Changes in stool consistency (ranging from loose and watery to hard and pellet-like)
Passage of mucus during bowel movements
Urgency – a sudden and intense need to defecate
Feeling of incomplete evacuation after a bowel movement

A notable characteristic of IBS symptoms is their correlation with changes in bowel movement frequency. Often, the discomfort associated with IBS is relieved, at least temporarily, following a bowel movement.

Exploring the Underlying Causes of Irritable Bowel Syndrome

While the precise cause of irritable bowel syndrome remains elusive, current understanding points towards a disruption in the communication between the nervous system and the bowel muscles. This irregular interaction seems to lead to an “irritated” or overly sensitive bowel. The muscles in the intestinal walls may exhibit abnormal contractions, being either too forceful, too weak, too slow, or too rapid at different times. Even in the absence of any physical blockage, these irregular muscle contractions can create the sensation of obstruction and cramping.

Irritable bowel syndrome is notably more common in women, occurring almost twice as frequently as in men. In some instances, IBS symptoms emerge following a bout of intestinal infection, a condition known as post-infectious IBS. Numerous factors have been considered as potential contributors to IBS, including:

Environmental influences
Genetic predispositions
Bacterial fermentation within the gut
Small intestinal bacterial overgrowth (SIBO)
Food intolerances
Altered bowel motility
Heightened intestinal sensitivity (visceral hypersensitivity)
Changes in nervous system processing of pain signals
Fluctuations in hormonal regulation

Recent research suggests that IBS is not triggered by a single mechanism but rather by a combination of different processes affecting the intestines. Intestinal irritants, such as poorly digested carbohydrates and fats, excessive bile acids, specific food intolerances, and genetic susceptibility to intestinal inflammation, may all play a role in the manifestation of IBS symptoms. These diverse factors can trigger reflexes within the intestines or bowel wall, leading to changes in intestinal function and secretion. Irritants can also stimulate nerve endings in the bowel wall, contributing to intestinal hypersensitivity and the sensation of pain.

The Role of Stress in Irritable Bowel Syndrome

It’s important to clarify that stress is not considered a direct cause of irritable bowel syndrome. IBS is not classified as a psychological or psychiatric disorder. However, emotional stress can certainly exacerbate or intensify IBS symptoms. Many individuals with IBS report an increase in symptom severity during periods of nervousness or anxiety. Therefore, while stress doesn’t cause IBS, managing and reducing stress levels in one’s life can be a valuable strategy for alleviating symptom burden.

Diagnosing Irritable Bowel Syndrome: Ruling Out Other Conditions

Currently, there is no single definitive test to diagnose irritable bowel syndrome. Instead, IBS diagnosis is often described as a “diagnosis of exclusion.” This means that other potential medical conditions with similar symptoms must be ruled out before IBS can be considered the primary diagnosis. However, specific criteria must be met to establish an IBS diagnosis. These include recurrent abdominal pain or discomfort experienced on average at least 1 day per week in the last 3 months, associated with two or more of the following:

Improvement of symptoms related to defecation
Onset of symptoms associated with a change in stool frequency
Onset of symptoms associated with a change in stool form (appearance)

A thorough medical history review and physical examination conducted by a healthcare professional, such as a gastroenterologist or colon and rectal surgeon, are crucial steps in excluding more serious conditions. Depending on the individual’s symptoms and medical history, diagnostic tests may include:

Blood tests
Stool tests
Flexible sigmoidoscopy or colonoscopy (to visualize the colon)
X-ray studies

Certain symptoms are not typical of IBS and warrant prompt medical evaluation to rule out other conditions. These “red flag” symptoms include:

Fever
Anemia (low red blood cell count)
Rectal bleeding
Unexplained weight loss
New onset of symptoms at age 50 or older
Nighttime symptoms that awaken the patient
Changes in the character or pattern of symptoms
Recent use of antibiotics
Family history of inflammatory bowel disease or colorectal cancer

In some cases, a trial of a lactose-free diet for a period of 2 weeks may be recommended to assess for lactose intolerance, as this condition can mimic IBS symptoms.

Treatment Strategies for Managing Irritable Bowel Syndrome

A crucial first step in managing what is irritable bowel syndrome is understanding that it is not a serious or life-threatening condition. This knowledge itself can help reduce anxiety and stress, which are known to worsen IBS symptoms. Stress management techniques, behavioral therapies, physical therapy, biofeedback, relaxation exercises, and pain management strategies can be beneficial in alleviating IBS symptoms for many individuals. Keeping a symptom diary can be helpful in identifying specific foods or other triggers that exacerbate symptoms. It’s important to reiterate that surgery is not a treatment for IBS.

The primary goal of IBS treatment is symptom relief and improved quality of life. Lifestyle adjustments can play a significant role. Regular exercise and consistent sleep patterns are often recommended. Dietary modifications are also frequently helpful. Certain dietary components, collectively known as FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols), have been identified as potential symptom triggers in IBS. FODMAPs include certain types of sugars like lactose, fructose, galactans, sorbitol, mannitol, and xylitol. A low-FODMAP diet can be beneficial for some people with IBS. Gluten intolerance, even in the absence of celiac disease, may also contribute to symptoms in some individuals. Gas-producing foods such as beans, cabbage, cauliflower, broccoli, Brussels sprouts, and onions can contribute to bloating and discomfort in people with IBS.

Dietary fiber’s role in IBS management is complex and can be both positive and negative. Soluble fiber, found in foods like citrus fruits, flaxseeds, and legumes, can help soften stools and potentially reduce cramping. Insoluble fiber, present in cellulose, cereals, and bran, can absorb water and help alleviate diarrhea. However, for some individuals, excessive fiber intake can worsen bloating and discomfort.

Probiotics, or “good bacteria,” are another avenue for potentially improving IBS symptoms. They can be used as a supplement to dietary changes. Probiotics are available in various forms, and it may take some experimentation to find the most effective type for an individual.

For individuals with moderate to severe IBS, prescription medications may be considered. It’s important to understand that no single medication works universally for all IBS patients. Medications that a doctor might prescribe include:

Anticholinergic medications to help reduce intestinal spasms, such as dicyclomine, hyoscyamine, and others. Potential side effects can include dry mouth, urinary difficulties, blurred vision, and rapid heartbeat.
Bisacodyl, a stimulant laxative, can be used for constipation relief.
Loperamide, an anti-diarrheal medication, can be used to manage diarrhea.
Low-dose antidepressants have shown to be helpful in some IBS patients, even those without depression.
Rifaximin, an antibiotic used for a short course (typically 2 weeks), has been shown to be effective in some individuals with IBS who do not have constipation, suggesting a potential role of gut bacteria in certain cases of IBS.

Timeline for Symptom Relief with IBS Treatment

It’s important to have realistic expectations regarding the timeline for symptom improvement in IBS. Relief is often a gradual process. It may take six months or longer to experience significant and sustained improvement. Patience is key when managing this condition. The underlying tendency for the intestine to react to stress may persist. However, with consistent attention to dietary modifications and, when necessary, the appropriate use of medications, the symptoms of irritable bowel syndrome can be significantly improved or even eliminated, leading to a better quality of life.

What Happens If IBS is Left Untreated?

Irritable bowel syndrome does not progress to more serious conditions, and it does not cause cancer, gastrointestinal bleeding, or inflammatory bowel diseases like ulcerative colitis or Crohn’s disease. However, if left unmanaged, the symptoms of IBS are likely to persist. These symptoms may fluctuate in intensity, improve or worsen over time, and continue to negatively impact an individual’s overall quality of life. Therefore, while not dangerous, addressing IBS symptoms is important for well-being.

Questions to Ask Your Doctor About IBS:

What is irritable bowel syndrome?
What are the potential causes of my IBS?
Is stress contributing to my IBS symptoms?
How is IBS diagnosed?
Are there specific tests to confirm IBS?
Do I need a colonoscopy or other diagnostic tests?
Is IBS considered a “serious illness”?
Can IBS lead to other serious health problems?
What are my treatment options for IBS?
Are there specific foods that might be affecting my symptoms?
Is it likely that my IBS symptoms will eventually resolve?

Understanding the Role of a Colon and Rectal Surgeon

Colon and rectal surgeons specialize in the surgical and non-surgical management of diseases affecting the colon, rectum, and anus. They undergo extensive surgical training in these areas, in addition to comprehensive general surgical training. Board-certified colon and rectal surgeons complete residencies in both general surgery and colon and rectal surgery and pass rigorous examinations conducted by the American Board of Surgery and the American Board of Colon and Rectal Surgery. They are experts in treating both benign and malignant conditions of the colon, rectum, and anus, proficient in routine screening procedures, and skilled in surgical interventions when necessary.

Disclaimer

The American Society of Colon and Rectal Surgeons is committed to promoting high-quality patient care by advancing the science, prevention, and management of disorders of the colon, rectum, and anus. These educational materials are intended to be informative and are not prescriptive. Their purpose is to provide information on medical conditions and processes, rather than to dictate a specific course of treatment. They are intended for use by healthcare professionals, patients, and anyone seeking information about the management of the conditions discussed. It should be recognized that these materials are not exhaustive of all appropriate methods of care, nor are they exclusive of reasonable approaches to achieving similar outcomes. The ultimate clinical judgment regarding the appropriateness of any specific procedure must be made by the physician in light of the individual patient’s circumstances.

Citations

Foxx-Orenstein, A. IBS: Review and What’s New. Med. Gen. Med. 2006: 8-20
Nikfar, S., et.al.: Efficacy of Probiotics as a Treatment in Irritable Bowel Syndrome: A Meta-Analysis of Randomized Controlled Trials. Dis. Col. Rectum; 51(12): Dec.2008; 1775-1780
Talley, N.: Dietary Modification as a Treatment for Irritable Bowel Syndrome. Gast. Hep.; Aug. 2012; 552-554
Pimentel, M., Lembia, A., Chevy, W.D., et. al.: Rifaxamin Therapy for Patients with Irritable Bowel Syndrome Without Constipation. N Engl J Med; 2011; 364: 22-32
Camilleri, M.: Peripheral Mechanisms in Irritable Bowel Syndrome. N Engl J Med 2012; 367: 1626-1635
Madhulika G. Varma and Brooke H. Gurland, Chapter 32,”Constipation and Functional Bowel Disorders”. Chapter in Beck, D. E., Roberts, P. L., Saclarides, T. J., Senagore, A. J., Stamos, M. J., Wexner, S. D., ASCRS Textbook of Colon and Rectal Surgery, 2nd Edition. Springer, New York, NY; 2011.