This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Collagenous gastritis (CG) is a rare condition that primarily affects the digestive system. People with CG have increased buildup of collagen in the subepithelial layer of the stomach. This condition typically affects children and young adults up to 22 years, or older adults over 35 years of age. Signs and symptoms appear to vary depending on the age group. Initial symptoms in children and young adults often include anemia and abdominal pain, whereas older adults often have chronic watery diarrhea associated with collagenous colitis, celiac disease or both. Adult collagenous gastritis is also associated with autoimmune diseases such as Sjögren syndrome, lymphocytic gastritis, lymphocytic colitis, and ulcerative colitis. Other signs and symptoms of CG may include nausea and vomiting, weight loss, abdominal distention, and gastrointestinal bleeding. The cause of the condition is unclear. Because of the small number of cases, no standard therapy for CG has been established based on randomized, controlled clinical trials.
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