Collagenous colitis: a recently recognised reversible clinicopathological entity.

Area of Science:

• Gastroenterology
• Colorectal Diseases
• Pathology

Background:

• Collagenous colitis is a rare condition characterized by a thickened subepithelial collagen layer in the colon.
• Previous case reports predominantly involved middle-aged women and identified the collagenous band primarily in the left colon.

Observation:

• This report describes an unusual case of collagenous colitis in an 86-year-old male presenting with watery diarrhea.
• The collagenous band was observed in both the right and left sides of the colon and was notably thicker than previously reported.
• The condition resolved within three months post-biopsy, coinciding with symptomatic treatment.

Findings:

• The collagenous band in this case extended throughout the colon, unlike previous reports.
• The patient experienced clinical improvement and resolution of the subepithelial collagenous band after treatment.
• This case represents the thickest collagenous band documented to date.

Implications:

• Collagenous colitis should be considered in the differential diagnosis for patients presenting with watery diarrhea, regardless of age or sex.
• Diagnosis requires histological confirmation via rectal or colonic biopsy.
• The findings suggest that collagenous colitis can occur in elderly males and may present with a more extensive collagenous band.