Ulcer pain mechanisms. The clinical features of active peptic ulcer disease and implications for therapy.

Pain is commonly the initial symptom in peptic ulcer, but the mechanism is controversial. Chemical irritation by hydrochloric acid (HCl) and disordered motor activity have been implicated. Questions have been raised as to whether pain is a good indicator of an active ulcer. We have studied the mechanism of ulcer pain, using intragastric administration of 0.1 N HCl, study of X-ray alterations, measurement of intraluminal pressures, and measurement of gastric acidity along with fluorocinematography. Ulcer pain was accompanied by a synchronous increase in motor activity; gastric emptying was rapid with duodenal ulcer and delayed with gastric ulcer; relief of pain occurred with emptying. Ulcer pain is not a good indicator of activity. Relief of ulcer pain before endoscopic healing with famotidine is due to the inhibition of HCl below the threshold required to initiate disturbances of motor activity. Recurrent 'silent' ulcer with complications occurs in 40% of patients.