Changes in the rectal mucosa induced by hypertonic enemas

Area of Science:

• Gastroenterology
• Histopathology

Background:

• Rectal mucosa changes after hypertonic enemas can be mistaken for quiescent ulcerative colitis.
• Establishing clear diagnostic criteria for enema reactions is crucial.

Purpose of the Study:

• To define diagnostic criteria for hypertonic enema reactions in rectal mucosa.
• To differentiate enema-induced changes from ulcerative colitis.

Main Methods:

• Retrospective analysis to derive criteria, prospectively tested on 11 healthy volunteers.
• Macroscopic and microscopic evaluation of rectal biopsies before and after sodium phosphate hypertonic enema.
• Blind assessment by three observers grading features and making diagnoses.

Main Results:

• Histologic diagnoses correctly identified enema effects, though macroscopic appearance was sometimes misclassified.
• Key features of enema reaction include mucous depletion, increased mucosal fragility, lamina propria edema, and basal membrane straightening.
• Focal erythrocytes in the lamina propria were observed in 39% of cases.

Conclusions:

• The effects of hypertonic enemas on rectal mucosa are recognizable on biopsy.
• Histologic examination is essential for accurate diagnosis, differentiating enema reactions from ulcerative colitis.