Distal esophageal contractile amplitude and duration after wet swallows increases with age. Triple-peaked waves and wet-swallow-induced simultaneous contractions should suggest an esophageal motility disorder. Double-peaked waves are a common variant of normal. Dry swallows have little use in the current evaluation of esophageal peristalsis.

Multichannel intraluminal impedance (MII) is a new technique for evaluation of bolus transport. We evaluated esophageal function using bolus transport time (BTT) and contraction wave velocity (CWV) of liquid, semisolid, and solid boluses. Ten healthy subjects underwent MII swallow evaluation with various boluses of sterile water (pH 5), applesauce, three different sized marshmallows, and iced and 130 degrees F water. The effect of bethanechol was also studied. There was no difference in BTT or CWV for all water volumes from 1 to 20 ml. There was significant linear increase of BTT with progressively larger volumes of applesauce, and BTT of applesauce was longer than for water. BTT was significantly longer with large marshmallows vs. small and medium and was longer than for water. BTT for iced water was similar to 130 degrees F water. Applesauce showed a significant linear decrease of CWV with progressively larger volumes and was slower than water. Marshmallow showed significantly slower CWV with the large vs. small, and CWV for ice water was significantly slower than 130 degrees F water. Therefore, BTT of liquid is constant, whereas BTT of semisolid and solid are volume dependent and longer than liquids. CWV of semisolids and solids are slower than liquids. CWV of cold liquids is slower than warm liquids. MII can be used as a discriminating test of esophageal function.

Graded intraesophageal balloon distension (IEBD) has been utilized in the past to evaluate esophageal pain thresholds. With use of a technique that we have found to provide reproducible results for pain thresholds, two groups of normal individuals without esophageal symptoms or diabetes were studied. Group 1 included 10 "young" (age < 65 yr) individuals (mean age 27 yr, range 18-57 yr). Group 2 included 17 individuals age 65 yr or greater (mean age 72.5 yr, range 65-87 yr). Catheters with latex balloons (Wilson-Cook) were used in all 27 subjects with the balloon located 10 cm above the lower esophageal sphincter. Sequential inflations of 2-ml increments were performed until a total volume of 2 ml above the point of pain or to a maximum of 30 ml was reached. A series of two sequential inflations were performed on each subject on the day of the testing, and the mean value was taken to indicate pain threshold volumes for all 27 subjects. In the group of elderly volunteers, 5 subjects felt no pain even at the maximum inflatable volume of the balloon (30 ml) and were assigned a maximum threshold value of 30 ml. Mean pain threshold volumes for the young subjects was 17 +/- 0.8 ml of air (+/- SE) and for the elderly subjects was 27 +/- 1.4 ml (P < 0.01 and 95% confidence interval = 7.1-13.3). Our conclusion is that IEBD results in the esophagus indicate an age-related decrease in human visceral pain threshold.

There has been renewed interest in the use of manometry of the pharyngoesophageal segment in the investigation of pharyngeal dysphagia. Advances in technology have alleviated previous difficulties presented by factors such as the rapid response rate of the striated muscle and asymmetry of the upper esophageal sphincter. Close attention to technique can overcome difficulties with movement artifacts encountered during deglutition. Manometry is being used to study normal swallow function and the effects of physiologic changes. There are also increasing numbers of reports in the literature of manometric studies in patients with oropharyngeal dysphagia. This technique provides information on pressure changes and augments that information obtained from a barium swallow.