S6123 Triple Threat: A Rare Combination of Collagenous Gastritis, Sprue and Colitis

Introduction: Collagenous sprue is a rare small bowel enteropathy first described in 1947, with only a few hundred cases reported. It presents with diarrhea, weight loss, and malabsorption, and should be considered in patients with negative celiac serology. We present a case of an 83-year-old woman diagnosed with collagenous sprue, collagenous colitis and collagenous gastritis. Case Description/Methods: An 83-year-old woman presented with postprandial watery diarrhea and a 22 kg unintentional weight loss over 1 year, unresponsive to dietary changes, including bananas, rice, applesauce, and toast diet. Her physical examination was unremarkable. Celiac serologies were negative, and C-reactive protein and fecal calprotectin were normal. Upper endoscopy and colonoscopy showed erythematous gastric body and antrum with diffusely scalloped duodenal mucosa. Duodenal biopsies revealed villous atrophy, inflammatory infiltrates in the lamina propria, and subepithelial collagen deposition consistent with collagenous sprue. Similar subepithelial collagenous thickening was seen in the gastric antrum and colon, consistent with concurrent collagenous gastritis and collagenous colitis. The patient was started on a tapering 9 mg budesonide regimen. Diarrhea improved but frequent bowel movements persisted with ongoing weight loss despite a good appetite. Open-capsule budesonide was resumed at 9 mg, and a gluten-free diet was initiated despite negative celiac markers. The patient reported improvement upon follow up 3 months later, with reduced stool frequency, formed stools and stabilized weight. Discussion: Collagenous sprue, colitis and gastritis are diagnosed histologically by subepithelial collagen proliferation of >10 mm with entrapment of cellular elements. While they may co-occur, all 3 are simultaneously present in only ∼13% of patients with collagenous sprue. Once considered a severe subtype of celiac disease, collagenous sprue is now regarded as a distinct entity, likely with an inflammatory etiology given its association with autoimmune conditions. There are no clear guidelines for management, with conflicting evidence derived from case reports. Some success has been noted with gluten-free diets and budesonide, while other options include thiopurines, TNF-a inhibitors, and tacrolimus. Though historically associated with poor outcomes, recent reports suggest up to 80% of patients may respond to treatment. Collagenous sprue should be considered in patients with malabsorption and negative celiac serologies, or in those who fail to respond to a gluten-free diet.