Irritable Bowel Syndrome with Diarrhea Predominance (IBS-D)

What is Irritable Bowel Syndrome with Diarrhea Predominance (IBS-D)?

IBS not to be confused with Inflammatory Bowel Disease (or IBD), is a cluster of symptoms consisting most commonly of:

  1. Abdominal pain or discomfort, often described as cramping that comes and goes and improves after a bowel movement,
  2. Abdominal bloating or distention,
  3. Diarrhea and/or constipation, and
  4. A change in bowel habits from what had previously been normal, including altered stool frequency or form, increased straining with bowel movements, and/or urgency to have a bowel movement.
  5. With IBS-D patients may notice frequent, loose bowel movements while awake, sometimes with a sudden urge to go to the bathroom, and sometimes with mucous seen mixed in with the stool.


What are the symptoms of IBS-D?

Typical symptoms include: frequent, loose bowel movements while awake, sometimes with a sudden urge to go to the bathroom, and sometimes with mucous seen mixed in with the stool.

Symptoms will typically be present for months or even years at the time of diagnosis.

Eating and stress will often make symptoms worse, and many patients will state that their digestive tract appears more sensitive to certain foods, medications, stress, and infections.

*Diarrhea that awakens a person from sleep is not typical of IBS-D and should be evaluated promptly by a physician. Additionally, any abdominal pain or warning symptoms such as weight loss, fevers, chills, sweats, dizziness, fatigue, back pain, pain at night, bleeding, iron deficiency anemia, or symptoms that start after the age 50 should be evaluated promptly and aggressively by a medical professional.

How common is IBS?

IBS is very common, occurring in roughly up to one in every five Americans, depending upon the source cited. It affects both men and women, but is more common in younger women, and presents more often at times of emotional turmoil or stress. It usually begins in late adolescence or early adulthood, and rarely appears for the first time after the age of 50.

What causes IBS?

IBS is defined as a functional disorder of the digestive tract, meaning it is not caused by any structural, anatomic, or biochemical abnormalities. There are no signs of the disease that can be seen or measured, and routine medical tests used to diagnose disorders of the gastrointestinal tract such as colonoscopy, upper endoscopy (EGD), ultrasound, cross sectional imaging tests (CT or MRI), serology and stool studies, are often normal. Yet, the GI tract is not functioning normally.

In many ways, IBS is a diagnosis of exclusion, and is best defined by what it is NOT.

  1. It is NOT an anatomical or structural defect.
  2. It is NOT an identifiable physical or chemical disorder.
  3. It is NOT a cancer and will not cause cancer.
  4. It is NOT the same thing as Inflammatory Bowel Disease (IBD, Crohn’s disease, or Ulcerative Colitis).

However, it is very real, and symptoms can significantly affect a person’s quality of life.

The exact cause of IBS-D is not fully understood but believed to be multi-factorial involving:

  1. GI motility,
  2. GI sensation,
  3. The gut-brain connection (and changes in how the gut and brain communicate),
  4. Changes in the gut’s immune defenses, and
  5. Altered gut microbiota (or gut flora)
  6. Some patients may develop symptoms after an infection. This is known as post-infectious IBS and symptoms can last for weeks to even years.
  7. Sensitivity to certain foods and food allergies may also play a role in the development of the disease for certain people.

With IBS there seems to be a dysfunction in normal bowel muscle contractility resulting in abnormal motility. Rapid contractions of the intestine causes stool to move through the digestive tract at a faster than desirable pace. This results in less time available for the large intestine to reabsorb water from food sources, leading to loose and/or watery stools. Not forceful enough contractions, or slowed contractions, cause the opposite effect in IBS-C resulting in constipation. In both conditions, abnormal muscle contractions or spasms can result in considerable pain for patients.

While stress and anxiety are not thought to cause IBS, external stressors, life situations, trauma, emotions, anxiety, depression, and other psychological variables can affect GI motility and sensation and play a role in the development of IBS symptoms.

How is the diagnosis made?

When other diseases of the GI tract have been ruled out, doctors rely on a tool called the Rome criteria to help them make the diagnosis of IBS. These criteria require that patients have had recurrent abdominal pain, on average, at least 1 day per week during the previous 3 months associated with 2 or more of the following:

  1. The pain is related to defecation and may be increased or unchanged by defecation,
  2. The pain is associated with a change in stool frequency, and/or
  3. The pain is associated with a change in stool form or appearance.
  4. Subtypes are based on how frequently a patient experiences very loose or very hard stools. If a patient experiences very loose stools greater than 25% of the time and very hard stools less than 25% of the time, this classifies as IBS-D.

How is IBS treated?

IBS is not life threatening. It can, however, significantly affect a person’s quality of life. There is no cure, so the goal of treatment is to reduce symptoms as much as possible.

Treatment options include:

  1. Dietary changes:
    1. Emphasizing a balanced diet to promote a healthy weight and an overall feeling of health and wellbeing,
    2. Avoiding processed foods,
    3. Minimizing alcohol,
    4. Eliminating artificial sweeteners such as sucralose,
    5. Patients are advised to avoid food triggers, which can vary between patients but most commonly include foods containing lactose and/or gluten (wheat, barley and rye).
    6. Some people are more sensitive to certain carbohydrates found in foods such as fructose, fructans, lactose and others, known as FODMAPs (or Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols). For some patients IBS symptoms may improve with following a strict low-FODMAP diet, then, reintroducing foods one at a time. If symptoms recur, patients will have a better idea which foods to avoid. Nutrition consultation may be helpful.
    7. Avoiding foods known to cause increased gas production including: cabbage, broccoli, cauliflower, onions, celery, carrots, beans, prunes, wheat, alcohol, caffeine, carbonated beverages, and raw fruit, may help. 
  1. Lifestyle modifications:
    1. Reducing stress,
      1. Stress and anxiety play a major role in IBS symptoms. Nerves in the colon control bowel contractions and GI motility. In times of stress these nerves can become over-stimulated resulting in abdominal pain and discomfort. Reducing stress and anxiety may improve symptoms. Cognitive behavioral therapy (CBT) and medication management may be beneficial for certain patients.
    2. Participating in regular exercise, and leading an active lifestyle.
      1. Exercise helps by improving overall wellbeing and helping to keep the digestive tract working properly, potentially improving constipation. Always talk with your doctor first before beginning any exercise routine.

In addition to lifestyle and dietary modifications, medications are often used to treat symptoms. Call 980-788-8200 for a comprehensive medical evaluation to determine the cause of your symptoms and to establish a treatment plan that works for you.

The information on this website is to provide general guidance. In no way does any of the information provided reflect definitive medical advice and self diagnoses should not be made based on information obtained online. It is important to consult a best in class gastroenterologist regarding ANY and ALL symptoms or signs as it may a sign of a serious illness or condition. A thorough consultation and examination should ALWAYS be performed for an accurate diagnosis and treatment plan. Be sure to call a physician or call our office today and schedule a consultation.

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