Over the years, I have heard from many IBS patients that they also deal with nervous system symptoms alongside their digestive symptoms. Often these symptoms occur in conjunction with bowel movements. This combination of nervous and digestive system dysfunction may be related to a health condition known as dysautonomia. Here is an overview of dysautonomia and its relationship with IBS.

What Is Dysautonomia?

Dysautonomia is thought to be present when the autonomic nervous system does not function as it should. The autonomic nervous system is the part of the nervous system that is responsible for most of the unconscious working of the various organs and systems of our bodies, including such processes as respiration, digestion, and heart rate.

The autonomic nervous system is broken down into the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is the part responsible for our "fight or flight" response, with its symptoms of rapid heart rate, fast breathing and changes to the way blood flow is directed through the body. The parasympathetic nervous system is the part that works to maintain regular body functioning. In dysautonomia, there can be excessive sympathetic activity, with a possible failure of parasympathetic activity, resulting in dramatic and disruptive symptoms. Dysautonomia can involve localized or full-body neurological dysfunction.

Dysautonomia is a catch-all term that encompasses many different health problems. In primary dysautonomia, there is a known injury to the nervous system secondary to an identified neurological illness. Secondary dysautonomias are those in which the neurological damage is the result of a non-neurological illness. Some dysautonomias are the result of medication side effects, while others are of unknown causes. Depending on the cause, dysautonomia can be short-term or chronic, and again, depending on the cause, improve or worsen over time.

Some identifiable causes of dysautonomia include:

Dysautonomia has also been associated with the following health problems:

Chronic fatigue syndrome (CFS)
Fibromyalgia
Inappropriate sinus tachycardia (IST)
Irritable bowel syndrome (IBS)
Panic disorder
Postural orthostatic tachycardia syndrome (POTS)
Vasovagal syncope

Dysautonomia is also known as "autonomic dysfunction," and when there is clear-cut damage to the autonomic nerves, as "autonomic neuropathy."

Symptoms of Dysautonomia

Dysautonomia can present itself in many ways. Orthostatic hypotension is seen as a classic symptom. This rapid drop in blood pressure when a person stands up results in a feeling of dizziness, weakness and in some cases, fainting. Other symptoms include:

Anxiety
Blurred vision
Discomfort during exercise
Dizziness
Excessive sweating
Fainting
Fatigue
Gastrointestinal symptoms
Impotence
Low blood pressure
Numbness
Rapid pulse rate
Sexual difficulties
Tachycardia
Tingling sensations
Urinary difficulties

Overlap With IBS

The research on the overlap of dysautonomia and IBS is limited. One published report involved a review of a large number of case-control studies that took measurements of markers of sympathetic nervous system functioning in a variety of health problems, including IBS, chronic fatigue syndrome, fibromyalgia, and interstitial cystitis. Such measurements included changes in heart rate and blood pressure, sweating, response to a tilt table test, and symptom questionnaires. Definitive answers from this review are clearly limited due to the wide variability of health problems, testing protocols and symptom measurements used in the case studies. However, it is notable that 65% of these studies found evidence of sympathetic nervous system hyper-reactivity. It is thought that chronic stress may contribute to the onset of these disorders, as well as to the dysfunction of the autonomic nervous system.

Interestingly, one small study found a "blunting" of autonomic system reactions to stimulation of the large intestine in IBS patients that was related to how long they had the disorder. This is in contrast to most published reports that show an increase in sympathetic reactivity to inner stimulation. It is unknown if this finding had to do with the type of stimulation used or if there are changes in autonomic reactivity over time.

As you can see by the lack of research in the area, little is known as to why a person would have both IBS and dysautonomia.

What to Do When You Have Both

If you think you may have dysautonomia, see your doctor and discuss your symptoms.

As of now, there is little in the way of pharmacological treatment for dysautonomia (or IBS for that matter). What is generally recommended for dysautonomia are therapies that may improve the functioning of your autonomic nervous system. Many of these are also helpful for IBS: