A type of colitis that occurs primarily in middle-aged women.
Collagenous colitis is a rare but treatable inflammatory disorder of the mucous membranes lining the colon. It is a poorly understood disorder that has not received much attention in the research (Microscopic/Collagenous Colitis FAQ, 1999). Collagenous colitis is often referred to as a form of microscopic colitis because it can only be detected by a pathologist using a microscope after a biopsy; with this condition during an endoscope procedure (colonoscopy or sigmoidoscopy), the colon looks normal. Collagenous colitis is also often referred to as lymphocytic colitis because it is characterized by a thickening of the subepithelial collagen layer and increased lymphocytes in the lining of the colon.
Chronic watery diarrhea of unknown cause, in which the appearance of the bowel during endoscopy is normal. Biopsies of the bowel wall reveal thickening of the collagen layer beneath the colonic epithelium. CC is much more common in women than in men by a factor of 10. It is usually diagnosed in people aged 40 to 60.