FAQ: What Are Functional Gastrointestinal & Motility Disorders?

If you've been reading about my experience at Digestive Health Alliance Advocacy Day, you've seen the term "functional gastrointestinal and motility disorders" or FGIMDs used frequently. Gastroparesis is one of several disorders that fall under the umbrella of FGIMDs. Others include functional dyspepsia, irritable bowel syndrome, chronic constipation, and intestinal pseudo-obstruction. Some patients have more than one FGIMD, for example GP and slow-transit constipation.

What connects all of these disorders is improper functioning of the muscles within the GI tract (myopathic) or of the nerves and hormones that control those muscles (neuropathic). Unlike organic diseases, you cannot see a functional or motility disorder by looking at the affected organ(s), doing x-rays or performing blood tests. In other words, there is no physical abnormality or obstruction that is causing the symptoms. For that reason, diagnosis tends to be based on patient-reported symptoms and exclusion of other possibilities.

Gastroparesis itself is a motility (movement) disorder characterized by slow emptying of the stomach. However, especially in cases of idiopathic gastroparesis, the severity of symptoms often does not correlate with the degree of delayed gastric emptying. Symptoms may be the result of additional functional issues. In some cases, gastroparesis can be difficult to distinguish from functional dyspepsia and some experts believe that they are variations of the same disorder.

While gastroparesis is thought to affect about 4% of Americans, FGIMDs in general are estimated to affect about 15% of the total population. Unfortunately, FGIMDs are disproportionately underfunded and under-researched. At this point, very little is understood about what causes the nerves and muscles of the GI tract to function improperly and adequate treatment options are therefore limited. Raising awareness of and support for gastroparesis in particular is important, but advancements made in any area of functional gastrointestinal and motility disorder research will ultimately benefit all of us.