Jejunal prostaglandin E2 secretion in patients with adult celiac disease was studied under basal conditions and after local gliadin challenge. A newly developed tube system with occluding balloons was used to perfuse a jejunal segment. After an initial basal perfusion period of 40 minutes, an average of 12 mg ± 3 (SEM) of crude gliadin was administered into the perfused segment. Perfusion continued for an additional 100 minutes and prostaglandin E2 was determined in the effluent with a radiometric method. Patients with histologically active celiac disease (n = 7) had higher basal jejunal secretion of prostaglandin E2,523 ± 229 pg · cm-1 · h-1(mean ± SEM), than both celiac patients with normalized small bowel mucosa (n = 6), 160 ± 44 pg · cm- · h-1, and healthy controls (n = 18), 184 ± 38 pg · cm-1 · h-1, (P < 0.05). After gliadin challenge of the jejunal segment, a significant increase (P < 0.05) in prostaglandin E2 secretion was noted in patients with celiac disease (n = 10). The individual maximum increase was on average fivefold and occurred 60-100 minutes after gliadin administration. In healthy controls (n = 5), no alteration in prostaglandin E2 secretion was detected after gliadin challenge. Enhanced jejunal prostaglandin 2 synthesis may be involved in the pathophysiological processes initiated by gliadin in patients with celiac disease. © 1990.