Gastrointestinal Motility - it's evaluation and clinical significance; an overview.

Disorders of gastrointestinal motor function are undoubtedly common but their evaluation and management continue to pose major challenges to the clinician and clinical investigator. Several factors contribute to this relative impasse. Firstly, symptoms suggestive of dysmotility are notoriously non-specific. For example, despite the use of a variety of validated survey instruments and large study populations, it has proven difficult to predict the presence of gastroparesis among those with functional dyspepsia. Other symptoms such as chest pain, dysphagia, abdominal discomfort and distension, which may be associated with dysmotility, may also be consequent on a myriad of “organic” disorders. In other areas, such as the assessment of constipation, symptom recall has proven remarkably unreliable in indicating bowel dysfunction perse. Secondly, diagnostic studies in the area of dysmotility consistently face a major obstacle the lack of a true “gold” standard. Thus, how can one make a manometric diagnosis of myopathy or neuropathy without recourse to histological confirmation? In this regard our pre-occupation with “functional” disorders has been a barrier to progress. Our time would have been better served by developing and evaluating diagnostic approaches among those with truly organic disorders or dysmotility (such as Chagas disease or scleroderma) than in devoting time and effort to arguments about the “significance” of various manometric features in patients with the irritable bowel syndrome. A similar dilemma applies to the diagnosis of non-erosive gastro-esophageal reflux disease (NERD). How does one confirm GERD in an individual without esophagitis? Finally, we are hampered by a relative paucity of therapeutic options. Furthermore, many of the available motility-modifying agents are relatively non-specific in their mode of action, thereby further diminishing the impact of diagnostic efforts. What is the way forward? I believe that we must attempt to place a much greater emphasis on the delineation of organic” dysmotility and hone our diagnostic skills and therapeutic efforts in this arena before moving into the less well defined “functional” disorders. More emphasis must also be placed on the histological evaluation of the myenteric plexus and intestinal smooth muscle. We must expand the range of clinical-pathologic correlations in gastrointestinal motility. Only then can we, truly, look forward to a time when the evaluation and management of dysmotility has a basis in pathology and pathophysiology.