The role of scintigraphic defecography in the assessment of bowel function after restorative proctocolectomy for ulcerative colitis.

BACKGROUND

The aim of the study was to evaluate the efficiency of defecation in patients with ileal pouch for ulcerative colitis by using the mean of scintigraphic defecography.

METHODS

Sixteen patients were classified into two groups according to the presence of good (group A) or poor (group B) pouch function. Emptying efficiency was calculated by scintigraphic defecography and measured as percentage of evacuation. This involves the use of up to 200 ml of an artificial stool made up of methyl cellulose paste labeled with 180 MBq of technetium-99 m (Tc-99 m) methylene diphosphonate. Potential causes of increased frequency in the absence of additional associated symptoms of dysfunction were excluded in all patients. Maximum tolerated volume (MTV) and balloon expulsion tests were also performed on all patients.

RESULTS

No patient in both groups showed evidence of organic pouch dysfunction. Percentage of emptying was higher in patients of group A (n=6) than in group B (n=10) (81+/-9 vs 71+/-9%, respectively, P<0.05; correlation, -0.51, P<0.04). Mean MTV was similar in the two groups (group A: 361+/-118 ml and group B: 338+/-77 ml, P=0.7). Results of the balloon expulsion test were normal in all patients except for one individual in group B.

CONCLUSION

In patients with ileal pouch for ulcerative colitis, increased frequency of defecation without any evidence of pouch dysfunction may be correlated with an alteration of emptying efficiency. Scintigraphic defecography is appropriate to use for investigation of this condition with no disadvantages for the patients.