Collagenous colitis associated with chronic constipation

We present a case in which the classical histopathologic features associated with collagenous colitis were present throughout the colectomy specimen of a 69-year-old woman operated on for life-long intractable idiopathic constipation. This patient had never suffered from episodes of watery diarrhea. The reasons for this paradox are unclear, but suggest that a thickened collagen table and damaged surface epithelium may not be entirely specific pathologic findings marking the clinicopathological syndrome of collagenous colitis.

Does irradiation produce irreversible changes in canine jejunal myoelectric activity?

We sought to determine whether acute irradiation-induced changes in jejunal myoelectric activity are reversible or chronic and progressive with repeated exposures. Five dogs underwent abdominal irradiation absorbing 938 cGy on four separate occasions, two weeks apart. Recordings of jejunal myoelectric activity were made before and 10-11 days after each irradiation exposure. Ten to 11 days after the first exposure, the animals recovered completely from the acute radiation syndrome, and the myoelectric activity returned to normal. After subsequent exposures, they developed chronic diarrhea, profound weight loss, and progressive changes in myoelectric activity. Slow waves exhibited highly variable configuration, had an irregular rhythm, and were frequently uncoupled. Spike burst activity, duration, and length of migration were reduced in association with abnormal motility patterns even though histologic abnormalities were mild. Such changes are likely to interfere with normal propulsion and contribute to impaired nutrition. The abnormalities suggest that irradiation causes dysfunction of one or more of the cellular elements involved in small bowel motility (muscle, nerve, and interstitial cells) prior to the development of severe histologic abnormalities or mechanical obstruction.

Radiation and indomethacin effects on morphology, prostaglandins, and motility in dog jejunum

Irradiation can have a profound effect on intestinal motor activity. Previous studies have suggested that prostaglandins may play some role in radiation-induced enteritis. The present study investigated the effects of abdominal X-irradiation with or without indomethacin treatment on jejunal myoelectric activity and prostaglandin synthesis by measuring the prostaglandin content of mesenteric arterial and venous plasma and in the intestinal lumen in dogs. After X-irradiation, venous concentrations and arteriovenous concentration differences of prostaglandin (PG)E2, PGF2 alpha, and 6-keto-PGF1 alpha increased markedly. The increased venous concentrations were in part attributable to increased mucosal and/or submucosal synthesis by inference from increased concentrations of these metabolites assayed from the jejunal lumen. Irradiation produced histological damage to the mucosa and submucosa and abnormalities in the migrating motor complex, jejunal slow waves, and a decrease in spike burst activity. Inhibition of prostaglandin synthesis by treating the animals with indomethacin reduced the severity of illness, the histological injury, and changes in myoelectric activity induced by irradiation. Such treatment should be evaluated further to treat patients exposed to large doses of irradiation.