What Is IBS?

irritable bowel syndrome IBS

Irritable bowel syndrome (IBS), not to be confused with the more serious IBD (inflammatory bowel disease), used to be considered a functional disorder of the intestines. That is to say that the small and large intestine is not functioning properly though there is little or no evidence of damage or structural abnormality. Irritable bowel syndrome is usually identified by a group of symptoms. This condition is often determined more by what it is not than by what it is. It is characterized by the predominant symptoms of abdominal pain, bloating and change in bowel habit, which alternates between diarrhea and constipation.

Recent research, however, is revealing a clearer picture of irritable bowel syndrome. Dysbiosis, or, more specifically, small intestinal bacterial overgrowth plays a large role in IBS and provides a unifying explanation for the diverse and variable symptoms that accompany it.

Another inaccuracy of IBS is that it is a psychological disorder. To the contrary, IBS is a very real physiological disorder—not a psychosomatic ailment as once believed. That is not to discount the emotional stress component, however. Some think IBS is a disorder of the enteric nervous system, involving the nerve supply in the brain and in the gut, that alters normal pain perception, so that the bowel becomes oversensitive to normal stimuli.

What Causes Irritable Bowel Syndrome?

The following factors may play a causative role in the development of IBS:

  • Dysbiosis (imbalance in intestinal flora—too many bad bacteria, not enough good bacteria)
  • Irregularities in intestinal hormones and nerves responsible for bowel motility (muscle contraction)
  • Bacterial, fungal or parasitic involvement
  • Stress
  • Dietary inadequacies
  • Food intolerances (allergies and sensitivities)
  • Undiagnosed lactose intolerance
  • Inadequate enzyme production
  • Reaction to medications (such as antibiotics, which destroy intestinal flora)

Dysbiosis is a common feature that is often at the base of the complaints that present themselves as irritable bowel syndrome. The one symptom that is seen in 92 percent of IBS patients is abdominal bloating and pain. This symptom has been identified as being caused by an increase in intestinal gas. While many IBS sufferers report increased bloating after a meal, many are still unable to identify a specific food trigger. This points to the role that gut bacteria play in intestinal fermentation.

Excess fermentation can occur when there is an imbalance between beneficial and pathogenic or opportunistic gut bacteria. Excessive intestinal fermentation has been found in a large portion of IBS patients. Dysbiosis explains both diarrhea and constipation that accompanies IBS. It also explains the recently identified pro-inflammatory immune response that is seen in IBS. And due to the increase in the leaky gut—which is caused by dysbiosis—toxins and undigested food particles enter the bloodstream, triggering inflammation that ultimately affects the brain. This can be explained by the close communication that occurs between the immune system and the autonomic nervous system, located both in and near the intestines. This gut-brain connection explains the psychological symptoms that are sometimes seen in those with IBS.

Interestingly, proton pump inhibitor (PPI) medication use is one possible cause of the dysbiosis that occurs in IBS. Many people with IBS also have acid reflux (GERD) or dyspepsia and take PPIs to control it. PPIs lower the amount of gastric acid in the stomach, however, which can lead to an overgrowth of pathogenic or opportunistic bacteria resulting in dysbiosis.

IBS is, at least partially, a disorder of intestinal motility. The normally rhythmic muscular contractions of the digestive tract become irregular and uncoordinated and interfere with the normal movement of food and waste material. Mucus and toxins can then accumulate in the intestines setting up a partial and temporary obstruction of the digestive tract by trapping gas and stools that, in turn, cause bloating, distention and constipation.

The colon of the IBS sufferer seems to be more sensitive and reactive to stimulation than that of most people. Intestinal spasms may result from ingestion of certain foods or medicines and from abdominal distention caused by gas. While these factors would not cause undue gastrointestinal stress for the average person, for the IBS sufferer they can be triggers of painful abdominal spasms.

IBS Enhanced Image
An enhanced rendering of the intestinal lining developing into leaky gut

Normally, eating causes contractions in the colon resulting in the urge to defecate within an hour after eating. For the person with IBS, however, the urge may come sooner, often accompanied by cramps and diarrhea. This is especially true if the meal is large and/or contains a high percentage of fat. Fatty foods—like meat, dairy products and oils—provide a strong stimulus of colonic contractions for the person with IBS. Interestingly, stress has a similar effect explaining its role in IBS.

There is evidence that food sensitivities and allergies may play a major causative role in IBS, for they are found in one-half to two-thirds of those afflicted with the disorder. The most common allergens are dairy products and grains (especially wheat and corn). Other foods that often trigger episodes of IBS are coffee, tea, citrus, and chocolate. Both nicotine and caffeine in any form may serve as gut irritants.

Over-consumption of alcohol may also trigger intestinal spasms in the person with IBS. Also, meals high in sugar can contribute to IBS by decreasing intestinal motility. A high percentage of people with IBS are intolerant not only to sucrose (table sugar), but also to other forms of sugar like mannitol, sorbitol, and fructose. Additionally, foods from the cabbage family (broccoli, Brussels sprouts, cauliflower, kale) may be irritating to the IBS sufferer because of their tendency to cause gas.

Lactose intolerance is also associated with IBS.

The true cause of IBS symptoms may, in some cases, be an undetected parasitic infection.

An estimated one out of five Americans suffer from irritable bowel syndrome (IBS).

What Are the Signs and Symptoms of IBS?

International conferences have been held to establish agreed-upon criteria by which functional bowel disease, of which IBS is one, can be recognized. These conferences have produced the Manning Criteria (named after Adrian Manning who proposed one set of criteria) and the Rome Criteria (named for the location of one of the conferences). (read more)

The Manning criteria are:

  • Relief of pain after defecating
  • Stools that are more frequent and looser at the start of episodes of abdominal pain
  • A sense of incomplete rectal evacuation
  • Passage of mucus with the stool
  • A sense of abdominal bloating

The Rome criteria added to the above:

  • Constant presence of abdominal pain and altered bowel habits
  • Presence of remaining symptoms 25 percent of the time

Although the above criteria are the official ones, in reality, patients presenting with variations of these symptoms may be diagnosed with IBS. These variations may include:

  • Constipation with or without pain
  • Pain associated with bowel movements
  • Painless diarrhea only
  • Alternating constipation and diarrhea

IBS sufferers may also experience other symptoms, such as:

  • Flatulence
  • Nausea
  • Vomiting
  • Headaches
  • Loss of appetite
  • Anxiety
  • Depression
  • Poor nutrient absorption (if diarrhea is severe)

The abdominal pain associated with IBS is often triggered by eating and accompanied by abdominal spasms. The person with IBS may feel an urgent need to move the bowels but be unable to do so.

Rectal bleeding is not a typical sign of IBS. If present in an IBS sufferer (who is correctly diagnosed), it may be due to a minor disorder such as hemorrhoids or a fissure (a crack in the lining where the rectum joins the skin around the anus). If rectal bleeding is present, it should be evaluated by a doctor.

Brenda’s Better Way to Treating IBS

Brenda Watson Gut VItal Flora Probiotics

A diagnosis of IBS has become a “trash basket” diagnosis for almost any digestive disorder in which cancer and serious bowel disease have been ruled out. This condition will require particular attention to symptoms, and investigation of underlying causes. Often food sensitivities, especially to wheat or dairy, and Candida overgrowth are underlying issues in IBS.

My own daughter had chronic IBS, and at age 30 she tried a gluten- and dairy-free diet. This completely cleared up her IBS symptoms. In some people, repeated antibiotic treatment in childhood sets the stage for a digestive imbalance that creates the symptoms of IBS later in life. In other cases, I have seen women develop IBS that was triggered by the hormonal changes that come with the onset of menopause.

In any case, by looking at your own personal history and getting to the underlying causes, solutions for this condition can be found. Take a look at your diet. I often suggest that people write out their complete food intake for one or two days, so that they can take a good look at what they are putting into their body. They can also track symptoms associated with certain foods. This can be a useful tool as you begin your journey. Be honest with yourself, and be willing to make the changes that are necessary to achieve good health.

IBS can show up in two forms – one that involves constipation, and one that involves diarrhea. It is important to distinguish which type of IBS you have. Protocols for treatment will be specific to your type.

Rule Out

  • Food sensitivities
  • Candida overgrowth
  • Parasites


  • Comprehensive stool analysis (CSA)
  • Food sensitivity test


  • During an acute phase of IBS, follow the Get Lean Phase of the Skinny Gut Diet Eating Plan which eliminates many of the common foods that can create symptoms in IBS. This diet can also be easily modified to exclude any foods that cause sensitivity.
  • For maintenance after healing, follow the Stay Lean Phase of the Skinny Gut Diet Eating Plan. If raw foods are a problem, lightly steam vegetables.


  • Exercise is very important and can help reduce pain levels. Low-impact walking, swimming and weight training are good.
  • Eat organic foods as much as possible. The GI tract of IBS sufferers is sensitive, so chemicals could have a negative effect.


  • Stress can be a major component of this disease, so find ways to reduce it with therapies such as meditation, yoga, deep breathing, massage, biofeedback, or music therapy.
  • Biofeedback may also be useful.
  • Acupuncture may be helpful as it targets the meridians associated with the digestive system, and it is also a stress reducer.
  • Colon hydrotherapy may be beneficial if the IBS condition results from an imbalance in the GI tract, or if you have the constipation-dominated IBS.