Chronic Diarrhea And Weight Loss In A 27-Year-Old: Highlighting Collagenous Gastritis As A Rarely Encountered Entity

A 27-year-old male with chronic diarrhea, weight loss, and hair loss was diagnosed with collagenous gastritis, a rare condition characterized by a thick subepithelial collagen band in the gastric mucosa. Initially misdiagnosed as lactose intolerance, further tests revealed elevated IgE and fecal calprotectin levels, and gastroscopy confirmed the diagnosis. Collagenous gastritis, more common in females, presents with nonspecific symptoms like abdominal pain and diarrhea, and diagnosis relies on histological features. Treatment typically involves symptomatic management or corticosteroids for refractory cases. This case underscores the under-recognition of collagenous gastritis due to its rarity and nonspecific clinical presentation.