Gut Dysmotility & Ehlers Danlos Syndrome
This week we will discuss the most common type of Ehlers-Danlos syndrome – the hypermobile type (hEDS, formerly also described as EDS type III or joint hypermobility syndrome), this is the type that most commonly presents to gastroenterology services.
As connective tissue is present throughout the body, many different structures around the body including the digestive tract can be affected by EDS. Connective tissue is present in the digestive tract and is essential to the passive mechanical movements needed to complete digestion. It has been suggested that any abnormalities in the connective tissues in the digestive tract are likely to alter the way in which it moves, which could contribute to the range of symptoms experienced by people with hEDS. Connective tissue is also present around the nerves of the digestive tract and abnormalities of this can potentially make the gut more sensitive. It is important to remember that whilst differences in the digestive tract function are likely to be present in hEDS, as yet diagnostic biomarkers have not been identified and more research is needed to better understand the nature and impact of connective tissue within the digestive system, particularly in the other subtypes of EDS.
The digestive tract starts at the mouth, and ends at the anus. Many aspects of the digestive tract can potentially be affected, including both the upper digestive tract (oesophagus, stomach and duodenum) as well as the lower digestive tract (small intestine, large intestine, colon and rectum). We frequently see patients who mainly have symptoms related to either the upper or the lower digestive tract only, and some research studies have found that a significant proportion of people with hEDS experience some kind of gastrointestinal symptoms.
What sort of gut problems can occur? The type, frequency and severity of digestive symptoms can vary greatly from person to person as everyone with hEDS is different. The most frequently reported problems affecting the upper digestive tract are acid reflux and chronic/recurrent indigestion with pain or discomfort and early fullness after meals. The lower digestive tract can present problems such as constipation, abdominal pain, bloating, diarrhoea and a feeling of general abdominal discomfort. Nausea and vomiting can occur alongside any of the symptoms described above.
Delayed gastric emptying / dysmotility
The term dysmotility is often used to describe abnormal movements (e.g. sluggish movements or spasm) of the gut. Some hEDS sufferers can have a sluggish stomach, which means that there is a delay in the emptying of stomach contents into the small bowel, and this is often referred to as delayed gastric emptying. Delayed gastric emptying can range in severity from mild to severe, with the most severe form called gastroparesis (paresis = paralysis). A portion of hEDS sufferers do have delayed gastric emptying, however only a few will be severe enough to be diagnosed with gastroparesis. Patients with a lot of bloating and/or fullness after meals or nausea and vomiting can be tested for delayed gastric emptying, but it is important to note that so far a link between hEDS and gastroparesis has not been categorically established.
In other patients increased sensitivity of the stomach may be a more common problem. Both dysmotility and increased sensitivity of the stomach can be associated with symptoms such as acid or bile reflux, bloating, early fullness during meals/extended fullness after meals and nausea.
Heartburn / reflux
There is some preliminary research that suggests that people with hEDS are slightly more likely to have a small hiatus hernia at the lower end of the oesophagus. This means that the upper end of the stomach slips into the chest cavity through a small hole (hiatus) in the diaphragm (the large muscle that separates the chest cavity from the abdominal cavity). This is quite a common finding and is usually not dangerous, but it can mean that the muscle that closes to stop food or liquid contents of the stomach from escaping back up into the oesophagus is somewhat inefficient, resulting in the acid reflux and/or heartburn symptoms, and this is called gastroesophageal reflux disease (GERD or GORD). However, it is also possible to experience reflux and/or heartburn symptoms without having a hiatus hernia. These symptoms can be associated with dysmotility, increased sensitivity of the oesophagus, or be experienced in isolation with none of these underlying causes.
Bloating
Abdominal bloating is a common symptom in people with hEDS, and although the underlying causes are not fully understood, it is thought that dysmotility may be a contributing factor. Overgrowth of bacteria of the small bowel can occur if there is stagnation within the bowel (i.e. constipation) and this can lead to excessive fermentation of food leading to production of gas, which can also be associated with bloating. A link between hEDS and bacterial overgrowth has not been categorically established and further research is required.
Constipation
Chronic constipation in adults is a common and debilitating problem and it is estimated that around 12 to 19% of the general population experience this, with females and the older population being more prone. Constipation is also common in patients with EDS and it is thought that a sluggish colon and difficulty with evacuation of the bowel are key causes. However there are often many factors inter-linked which can contribute to constipation such as diet, metabolic (hormone) or neurological (nerve) conditions, side effects of prescription medications, particularly opioid-based painkillers, or physical disorders such as prolapse of the bowel.
Rectal and genital prolapse are recognised as potential problems for some people with hEDS, and can be a factor contributing to constipation. Prolapse of the rectum means that the lining (mucosa) of the rectum (called a partial prolapse) or the entire rectal wall (called a complete prolapse) protrudes into the rectum, which interferes with the ability for a stool to be passed. Prolapses of the rectum usually occur during bowel movements, and then recede, but more advanced rectal prolapses can occur upon standing as well. However, in most cases prolapses tend to be small and do not require any active interventions. If a significant prolapse is diagnosed upon testing, and it is thought to be contributing to your gastrointestinal problems, your physician will refer you to a surgeon.
Functional gastrointestinal disorders
Sometimes people with hEDS who have symptoms such as reflux, heartburn, constipation or nausea may not have an identifiable cause of their symptoms on any medical testing and these patients are then given a diagnosis of functional gastrointestinal disorder (FGID). Patients who have symptoms with no underlying cause found account for more than a third of new referrals to gastrointestinal specialists, and so this is a common occurrence. A preliminary study amongst patients who were referred to a specialist because no cause of their symptoms could be found, demonstrated that over a third of those patients met the criteria for joint hypermobility and many of them had previously received a diagnosis of irritable bowel syndrome (IBS) or functional dyspepsia. IBS is the most common example of a FGID, and is characterized by recurrent abdominal pain and frequent changes in bowel habits. Functional dyspepsia is another type of FGID and relates to symptoms of upper abdominal pain, fullness, nausea and bloating, frequently following meals.