What is the differential diagnosis (Ddx) for a patient with new bloody stools and cholangitis, status post (s/p) stent placement and sphincterotomy?

Differential Diagnosis for New Bloody Stools Post-ERCP with Stent and Sphincterotomy

The most likely diagnosis is post-sphincterotomy hemorrhage, which occurs in 0.1-2% of cases and can present as immediate or delayed bleeding manifesting as hematemesis, melena, or hematochezia. 1

Primary Post-Procedural Complications

Post-Sphincterotomy Bleeding

• Hemorrhage is the most common cause of bloody stools following sphincterotomy, occurring in 0.1-2% of procedures and can be immediate or delayed by several days. 1, 2
• Risk factors include:
  • Coagulopathy or bleeding observed during the procedure 1
  • Initiation of anticoagulant therapy within 3 days post-procedure 1
  • Active cholangitis at time of procedure 1
  • Low endoscopist case volume 1
• Delayed bleeding can occur up to several days after sphincterotomy, making this a critical consideration even if the procedure was not recent. 2

Stent-Related Complications

• Stent migration can cause intestinal perforation and bleeding, particularly in patients with anatomical abnormalities like diverticular disease. 3
• Transpapillary stent placement across the main duodenal papilla increases risk of cholangitis and may contribute to mucosal trauma. 4
• Stent-induced duodenal or biliary mucosal erosion can cause bleeding. 3

Secondary Gastrointestinal Sources

Upper GI Bleeding

• Duodenal ulceration from instrumentation trauma during ERCP
• Hemobilia from percutaneous procedures or stent-related biliary trauma 1, 5
• Stress-related mucosal disease in the setting of acute cholangitis and sepsis

Lower GI Bleeding

• Colonic perforation from migrated stent with associated bleeding 3
• Ischemic colitis in the setting of sepsis/hypotension from cholangitis
• Coincidental lower GI pathology (diverticulosis, hemorrhoids, colitis)

Infection-Related Causes

Recurrent/Persistent Cholangitis

• Stent occlusion causing recurrent cholangitis is common, with plastic stents typically occluding after 5 months. 6
• Bacterial cholangitis occurs in 62% of patients with high-grade strictures and indwelling stents. 1
• ERCP with stenting is a major risk factor for bacterial cholangitis, with stented patients having 12% cholangitis rate versus 3% with balloon dilation alone. 1
• Sepsis-related coagulopathy can contribute to bleeding

Diagnostic Approach

Immediate Assessment

• Determine bleeding severity and hemodynamic stability - this dictates urgency of intervention 7
• Assess for signs of ongoing cholangitis (fever, right upper quadrant pain, jaundice) 2
• Check coagulation parameters and platelet count 1

Localization Studies

• Upper endoscopy (EGD) should be performed first to evaluate for post-sphincterotomy bleeding, duodenal ulceration, or hemobilia 1
• CT abdomen/pelvis to assess for:
  • Stent position and migration 3
  • Biliary dilation suggesting stent occlusion 6
  • Perforation or abscess 5
• Colonoscopy if upper source excluded and bleeding continues

Laboratory Evaluation

• Complete blood count with differential 7
• Liver function tests and bilirubin to assess for biliary obstruction 7
• Blood cultures if fever present 7

Management Priorities

Hemorrhage Control

• Endoscopic hemostasis is first-line for post-sphincterotomy bleeding, using injection therapy, thermal coagulation, or hemoclips 1
• Correct coagulopathy and hold anticoagulation if possible 1
• Angiography with embolization for refractory bleeding

Biliary Decompression

• If stent occlusion is present, urgent ERCP with stent exchange is indicated to treat cholangitis and prevent sepsis 6
• Broad-spectrum antibiotics covering gram-negative and gram-positive organisms 1, 7

Critical Pitfalls to Avoid

• Failing to recognize delayed post-sphincterotomy bleeding that can occur days after the procedure 2
• Assuming all bleeding is from the sphincterotomy site without excluding stent migration or perforation 3
• Underestimating the severity of cholangitis in patients with occluded stents - these patients can rapidly deteriorate 6
• Not obtaining bile cultures during repeat ERCP, which guides antibiotic therapy 1
• Delaying endoscopic evaluation in hemodynamically stable patients - early diagnosis improves outcomes 1