lower gastrointestinal hemorrhage

Etiology

• 80-85% of rectal bleeding is colorectal in origin
• diverticulosis/diverticulitis* (30%)
• angiodysplasia* (3%)
  • Osler-Weber_Rendu syndrome
• colorectal carcinoma*
• colonic polyps
  • polypectomy (8%)
• inflammatory bowel disease* (9%)
  • Crohn's disease
  • ulcerative colitis
• ischemic colitis (mesenteric ischemia)* (12%)
• infectious colitis*
• aortoenteric fistula*
• Dieulafoy lesion*
• intussusception*
• Meckel diverticulum*
• colorectal varices
• anorectal diseases
  • hemorrhoids - internal, external (14*)
  • anal fissure
  • anal fistula
  • rectal prolapse
  • rectal carcinoma*
  • rectal polyps
  • proctitis - ulcerative, infectious (6%)
  • cryptitis
  • draining perirectal abscess (pilonidal cyst)
  • dermatologic conditions

* sources of severe lower GI bleed

* 10% of severe lower GI bleed has an upper GI source

Epidemiology

• less frequent cause of acute GI bleed than upper GI bleed

History

• duration, quantity & color of bleeding, change in bowel habits or stool caliber, abdominal pain, fever, constipation, diarrhea, epistaxis, weight loss, nausea/vomiting, fecal mucus, fecal pus, tenesmus, lightheadedness, hematemesis, anorectal pain, easy bruising, recent antibiotics (C difficile colitis), NSAID use, anticoagulants, diverticulosis, hemorrhoids, colitis, peptic ulcer disease, heartburn, bleeding disorder, colonic polyps, cirrhosis, alcoholism

Clinical manifestations

• character of blood
  • hematochezia
    • bright red blood per rectum (BRBPR):
      • distal colorectal or anorectal source of bleed
    • maroon stools: proximal colon, small intestine,distal colon if associated with constipation
  • melena: GI bleeding proximal to the cecum
  • blood clots suggest lower GI bleed vs upper GI bleed
  • fecal occult blood
• signs & symptoms of blood loss
  • hypovolemia
  • anemia
• association of pain
  • painless bleeding
    • diverticulosis
    • angiodysplasia
    • internal hemorrhoids
  • abdominal pain
    • epigastric pain: peptic or gastric ulcer, gastritis, esophageal varices, Mallory-Weiss tear
    • periumbilical pain: small bowel, consider ischemic bowel if history of arteriosclerosis
    • hypogastric: colonic lesions
    • suprapubic: retrosigmoid lesion
    • generalized: ruptured abdominal aortic aneurysm with aortoenteric fistula, also back, patient appears critically ill
    • left-lower quadrant
      • descending colon or sigmoid lesions
      • ischemic colitis, ulcerative colitis
    • crampy with bloating: inflammatory bowel disease
    • colicky patient: intussusception
  • sacral pain
    • sharp pain after bowel movement: anal fissure
    • constant throbbing pain: perirectal abscess, acute, thrombosed external hemorrhoids
• change in bowel habits
  • constipation
    • chronic: hemorrhoids
    • new onset & progressive: distal colonic annular-constricting carcinoma
    • voluminous hard stool with pain: anal fissure
  • diarrhea
    • frequent bloody bowel movements +/- mucus:inflammatory bowel disease
    • with pus: infectious colitis or proctitis
  • tenesmus: anorectal lesions, i.e. proctitis, neoplasm
  • mucopurulent discharge +/- foul odor: perirectal abscess/ cryptitis, anal fistula, pilonidal cyst
  • change in shape of stool: anal or rectal carcinoma
  • sensation of rectal fullness, incomplete evacuation or recognition rectal mass: rectal carcinoma, hemorrhoids
• abdominal examination
  • distention: ruptured aneurysm
  • pulsating mass: aneurysm
  • epigastric tenderness: peptic ulcer
  • hepatomegaly: metastatic colon cancer
  • ascites: metastatic colon cancer
  • sausage-shaped right-sided mass: intussusception
  • diffuse mild tenderness without guarding: colitis
  • left-lower quadrant tenderness: sigmoid colon lesion
  • mass in region of colon: colon carcinoma
  • hyperactive bowel sounds: colitis, obstruction
• rectal examination
  • hemorrhoids external, prolapsed internal
  • draining sinus tract
    • pilonidal cyst
    • anal fistula
  • perirectal abscess
  • mass in rectum

Laboratory

• fecal occult blood
• anoscopy
• complete blood count (CBC)
• serum chemistries: iron, TIBC, % Fe saturation

Diagnostic procedures

• proctoscopy
• flexible sigmoidoscopy
• colonoscopy within 24 hours challenged
  • oral bowel preparation
  • identifies source of lower GI bleed in 2/3 of cases
• colonoscopy after 24 hours non-inferior to colonoscopy within 24 hours
• upper endoscopy for hematochezia with hemodynamic instability
  • CT angiography if upper endoscopy does not show source of bleeding
  • gastric lavage can identify brisk upper gastrointestinal hemorrhage

Radiology

• abdominal CT with contrast
  • rule out aortoenteric fistula
• CT angiography
  • initial diagnostic test in hemodynamically unstable* patients within 4 hours
  • initial unenhanced scan (to document preexisting intraluminal hyperattenuating material), followed by both arterial & portal venous phase scanning
  • diagnostic yield higher than RBC scintigraphy, but exposes patients to more radiation
• angiography (arteriography)
  • identification of bleeding lesion with CT angiography
  • infusion of vasoconstrictors to stop bleeding
  • transcatheter embolization to stop bleeding
  • catheter angiography should be performed within 90 minutes of CT angiography
• Tc-99m labeled erythrocyte scan (sensitivity 70%)
• air-contrast barium enema
  • barium should be avoided in initial diagnostic procedures because it precludes angiography or colonoscopy until the barium clears

* 'improvement in vital signs' does not correct hemodynamically instability

Complications

• most cases of lower GI bleed resolve spontaneously & have good outcomes
• older patients & comorbidities increase risk for complications
• 1-year risk for colorectal cancer after lower GI bleed is 3.7% if < 65 years & 8.1% if > 75 years, regardless of anticoagulation status

Differential diagnosis

• 10% of patients with rapid rectal bleeding have an upper GI source

Management

• general measures as outlined in gastrointestinal hemorrhage
• indications for hospitalization
  • age >= 60 years
  • hemodynamic instability
    • see Radiology: & Diagnostic procedures: above for hemodynamic instability
  • gross rectal bleeding
  • no obvious anorectal source of bleeding
  • if bleeding stopped & colonoscopy within past year excludes malignancy, safe for discharge
• nasogastric aspiration of gastric contents to rule-out upper GI source of bleeding is the 1st diagnostic preocedure
  • may be left in place for colonic lavage
  • upper gastrointestinal endoscopy if massive lower GI bleed with hemodynamic instability
    • abdominal angiography for massive lower GI bleed
• colonoscopy should generally be the 2nd diagnostic procedure
  • no evidence of active bleeding or hemodynamic instability
  • within 24 hours of presentation
  • attempt to normalize blood pressure & heart rate prior to gastrointestinal endoscopy
  • bleeding generally resolves within 24 hours at which time semi-elective colonoscopy can be performed
  • colonoscopy within 24 hours when bleeding is ongoing
  • urgent colonoscopy within 12 hours of presentation not beneficial
  • urgent colonoscopy not associated with differences in identification of bleeding source, adverse events, rebleeding, transfusion, or mortality
  • no outcome differences between early versus elective colonoscopy
  • colonoscopy identifies source of bleeding in 2/3 of patients
  • include terminal ileum intubation during colonoscopy
  • hemostatic clips are preferred over thermal treatments for diverticular bleeding
    • rubber band ligation & over-the-scope clips ok
  • argon plasma coagulation for angiectasia, with pretreatment submucosal injection for right colon lesions
  • do not use epinephrine injection as sole treatment for active bleeding
  • preparation:
    • 4-6 liters of a polyethylene glycol-based solution until rectal effluent is clear
    • when necessary, use a nasogastric tube to deliver lavage
      • accompany it with prokinetic agents
      • aspiration precautions in the elderly
• most cases of lower GI bleeding are self-limited
  • early rebleeding is common
• persistent acute lower GI bleeding
  • angiographic embolization
  • infusion of vasopressin
• general transfusion goal: blood hemoglobin > 7 g/dL; > 8 g/dL
  • consider > 9 g/dL if massive bleeding or cardiac ischemia
  • consider co-transfusion of platelets & fresh frozen plasma in patients receiving > 10 units of packed red blood cells in a 24-hour period or >= 3 units within 1 hour
  • similar outcomes of restrictive vs liberal transfusion
• specific measures for specific etiologies
• also see algorithm for management of GI bleed
• prevention of bleeding recurrence
  • high-dose proton-pump inhibitor for 3 days if bleeding ulcer
  • discontinue nonaspirin NSAIDs
  • discontinue aspirin for primary prevention
  • continue aspirin after bleeding cessation for secondary prevention of cardiovascular disease
  • high-risk patients with history of thromboembolic events:
    • consult cardiology, hematology, neurology ...
  • anticoagulation
    • unless hospitalization required, anticoagulation may continue
    • if hospitalized, hold anticoagulation on admission, restart in 7 days
    • if life-threatening bleed, on warfarin & require reversal, use prothrombin compex concentrate vs fresh frozen plasma
    • if life-threatening bleed, on direct oral anticoagulant who remain hemodynamically unstable, use reversal agent (idarucizumab, andexanet alfa) if available

More general terms

• gastrointestinal hemorrhage

More specific terms

• hematochezia; bloody stool, maroon stool

Additional terms

• bright red blood per rectum (BRBPR)
• melena

Patient information

lower gastrointestinal hemorrhage patient information