Role of the faecal stream in the maintenance of Crohn's colitis.

The role of the faecal stream in the maintenance of the inflammation in Crohn's disease has been studied. Small bowel effluent and a sterile ultrafiltrate of it were reintroduced into the defunctioned colon of patients with Crohn's colitis treated by split ileostomy. The systemic effect of these challenges on the patients was assessed clinically and by laboratory tests, and the effect on the local disease was assessed by endoscopy, histology, and quantitative analysis of lamina propria plasma cell populations. There was little response to the ultrafiltrate challenge. In contrast the clinical responses to challenge with ileostomy effluent were marked in some patients. One patient relapsed and eight others had clinically detectable responses. On the other hand changes in laboratory, endoscopic, histological, and morphometric tests in response to the faecal challenge were less pronounced. The only significant changes in the laboratory results were a relative lymphopenia (p less than 0.05) and a raised ESR (p less than 0.02) after seven days challenge with the effluent. The plasma cell density also increased but not significantly. In conclusion, these results suggest that factors greater than 0.22 microns in the faecal stream are responsible for the maintenance and exacerbation of inflammation in Crohn's disease.