II. Definitions
- Lower Gastrointestinal Bleeding
- Bleeding distal to the ligament of treitz (suspends the distal duodenum) at the duodenojejunal flexure
III. Epidemiology
- Incidence: 20 to 30 per 100,000 patients
- Hospital admission rate: 20 to 30 (up to 80) per 100,000 patients
- Lower GI Tract account for 20-30% of Gastrointestinal Bleeding sources
- Two thirds of Lower GI Bleeds originate in the colon, Rectum or anus (remainder from the Small Bowel)
IV. Causes: Adults with Acute Massive Rectal Bleeding
- Precaution: Consider Upper Gastrointestinal Bleeding source
-
Diverticular Bleeding (10-20%, up to 40% of cases in some studies, most common cause)
- Acute, severe painless bleeding, especially with known Diverticular Disease (approaches 50% in over age 60 years)
- Increased risk with advancing age and comorbidities (e.g. CAD, CKD, DM, Cirrhosis, cancer)
- Increased risk with NSAIDs, Aspirin and other antiplatelet agents (e.g. Plavix)
- Bleeding spontaneously ceases in 75%, recurs in 38%
- Recurrence is 9% at one year and 25% at 4 years
-
Angiodysplasia, angioectasias or Arteriovenous Malformations (3-12%)
- Recurrent painless bleeding, especially in over age over 60 years
- Self resolves in 40-45% of cases, and persistent cases are treated with endoscopic coagulation or electrocautery
-
Colon Cancer (2-26%)
- Slow chronic blood loss with change in bowel habits (esp. age >60 years old, positive Family History)
- May be associated with weight loss, chronic Anemia, incomplete emptying
-
Inflammatory Bowel Disease (10%)
- Bloody Diarrhea with recurrent crampy Abdominal Pain and weight loss
- Bleeding is more common with Ulcerative Colitis than with Crohns Disease
-
Ischemic Colitis (16 to 24%)
- Self-limited bloody Diarrhea, followed by acute, recurrent lower Abdominal Pain and weight loss
- Seen in cardiovascular disease patients (including Aortic Stenosis)
- May be foretold by prior hypotensive event
- Ischemic Colitis is missed as Hematochezia cause in up to 80% of patients ultimately diagnosed with the condition
- Rectal ulcer
- Hard stool induced Pressure Ulcers
- More common in Immunocompromised patients and with Sexually Transmitted Infections
- Acute Infectious Colitis
- Bloody Diarrhea with fever (Inflammatory Diarrhea or Dysentery), and travel history or food exposures
- Causes include Campylobacter jejuni (most common Bacteria), Salmonella, Shigella, Shiga-toxin producing E. coli
- Other inflammatory causes include Clostridium difficile, Entamoeba histolytica and Yersinia
-
Pseudomembranous colitis (or other Infectious Diarrhea or Dysentery)
- Bloody Diarrhea with fever and risk factors (recent Antibiotics, suspect oral intakes)
-
Radiation Colitis
- May be delayed 3 years after Radiation Therapy
- Post-polypectomy bleeding
- Self-limited bleeding, usually follows polypectomy or other bowel procedure within 30 days
- Associated with restarting NSAID or Aspirin too soon after Colonoscopy with polypectomy
-
Aortoenteric Fistula (Aortic Graft-Enteric Fistula)
- Occurs in those with aortic surgery history
- Requires immediate emergency management (untreated cases have mortality rates approaching 100%)
-
Internal Hemorrhoid (<10%)
- External Hemorrhoids may also cause bleeding, but are painful and with obvious source unlike Internal Hemorrhoids
- See evaluation below regarding precautions in attributing Gastrointestinal Bleeding to Hemorrhoids
- More common at ages 45-65 years old
V. Causes: Adults with chronic intermittent GI Bleeding
- Hemorrhoids (Up to 59%, includes external and Internal Hemorrhoids)
- Colorectal polyps (38 to 52%)
- Diverticulosis (34 to 51%)
- Colorectal Cancer (up to 8%)
- Ulcerative Colitis
- Arteriovenous Malformations
- Colonic stricture
VI. Causes: Adults - most commonly missed lower GI sources
- Arteriovenous Malformations
- Neoplasms in colon
VII. Causes: Children
- Anal Fissure
- Infectious Colitis
- Inflammatory Bowel Disease
- Colonic Polyps
- Intussusception
- Gastrointestinal Foreign Body (e.g. Button Battery)
- Arteriovenous Malformation
-
Meckel's Diverticulum (Ileal Diverticulum)
- Most common congenital GI abnormality
- Strongly consider in children with Lower GI Bleeding (esp. age <10 years old, or with intussception)
- Consider Technetium 99m Scan
VIII. History
- See Gastrointestinal Bleeding
- Distinguishing severe from mild lower intestinal bleeding may be difficult on initial presentation
- Ask to see photos of home output if available
- Findings that may suggest more severe bleeding
- Blood clots
- Bloody rectal output without stool (may also be distal rectal source, e.g. Hemorrhoids)
- Continuous bloody output
IX. Signs
-
Hematochezia (bright red blood in stool)
- Upper Gastrointestinal Bleeding source in 5-11% of patients
- Normal Bowel Sounds
- Hemodynamic status is typically more stable than in Upper GI Bleed
- Orthostasis may however be seen in one third of patients
- Brisk, life-threatening bleeding may still occur in Lower GI Bleeding (e.g. Diverticular Bleeding)
- Nasogastric lavage and aspirate is clear except for bile
- Not typically recommended to differentiate upper from lower GI source (poor efficacy)
- Nasogastric aspirate is in contrast positive in Upper Gastrointestinal Bleeding
-
Rectal Exam
- Perform in all Hematochezia patients, but often nondiagnostic (may miss severe intermittent GI Bleed)
X. Labs
- Serum Electrolytes
- BUN to Creatinine ratio >33 suggests Upper Gastrointestinal Bleeding source
- Normal Renal Function tests (BUN to Creatinine ratio normal) is typically normal in Lower Gastrointestinal Bleeding
- However, prerenal Azotemia may also occur in Dehydration (e.g. Acute Inflammatory Diarrhea)
-
Complete Blood Count
-
Hemoglobin or Hematocrit decreased in 50% of patients
- Usually less depressed than in Upper Gastrointestinal Bleeding
-
Hemoglobin or Hematocrit decreased in 50% of patients
- Coaulation Studies
- Partial Thromboplastin Time (PTT)
- Prothrombin Time (PT/INR)
- Preparation for Blood Transfusion
- Consent for Blood Products
- Type and Crossmatch for Packed Red Blood Cells (pRBC)
- Assessment of comorbidity and secondary complications
- Other diagnostic tests
- Fecal Calprotectin
- Indicated in the evaluation of Inflammatory Bowel Disease (positive if >250 mcg/g)
- Acute Inflammatory Diarrhea Causes
- Enteric Bacteria stool PCR testing
- Clostridium difficile Toxin (if recent Antibiotics)
- Entamoeba histolytica (travel to tropical Africa, Asia or Latin America)
- Fecal Calprotectin
XI. Evaluation: Hemodynamically Unstable (Tachycardia, Hypotension)
- See stabilization in management below
- Criteria
- Heart Rate >100
- Systolic Blood Pressure <115 mmHg
- Capillary Refill >3 seconds
- Two or more comorbid conditions
- Shock Index (HeartRate/SystolicBP) >1
XII. Evaluation: Hemodynamically Stable
- Painful Bleeding
- Fever, Diarrhea and possible exposures (food, recent travel)
- Infectious Colitis (Dysentery) evaluation with Stool Culture or enteric Bacteria and virus PCR panel
- Vascular disease risk factors in an older patient with pain out-of-proportion and symptoms recurrent with eating
- Ischemic Bowel disease evaluation with CT Abdomen with contrast, Colonoscopy
- Intermittent Abdominal Pain, weight loss in a younger patient
- Inflammatory Bowel Disease evaluation with Fecal Calprotectin and Colonoscopy
- Pruritus Ani with bleeding occurs after stooling
- Evaluate for Hemorrhoids with Anoscopy (and ask patient to perform valsalva during exam)
- Anemia is rare with Hemorrhoidal bleeding
- Precaution: Bleeding Hemorrhoids may be concurrent with a more proximal, serious bleeding source
- Colonoscopy is not typically needed in suspected Hemorrhoids in age <40 without red flags
- Red flags include weight loss, fever, Anemia, colon cancer Family History, refractory course
- Fever, Diarrhea and possible exposures (food, recent travel)
- Painless Bleeding
- Intermittent bleeding with weight loss and changes in bowel habits
- Colon Cancer evaluation with Colonoscopy
- Acute painless bleeding with history of Diverticular Disease
- Diverticular Bleeding evaluation with Colonoscopy
- Polypectomy in the last 30 days
- Post-polypectomy bleeding evaluation with Colonoscopy
- Intermittent bleeding with weight loss and changes in bowel habits
- Tools
XIII. Management: Acute Gastrointestinal Bleeding
- Precaution
- Brisk persistent bleeding occurs in up to 19% of cases
- Severe Hematochezia leads to a >=2 g Hemoglobin decrease in 24 hours, or >=2 unit pRBC required
- Initial Stabilization
- Obtain early Consultation with Gastroenterology or General Surgery for brisk Gastrointestinal Bleeding
- ABC Management
- Oxygen Supplementation
- Obtain two large bore peripheral IVs (14-16 gauge)
- Obtain acute labs as above
- Stabilize with crystalloid (e.g. Normal Saline) as needed for hemodynamic instability while Blood Products pending
- However, blood is far preferred as soon as it is available
- Avoid excessive crystalloid prior to transfusion
- Telemetry monitoring with Heart Rate, Oxygen Saturation and Blood Pressure Monitoring
- May also obtain Orthostatic Blood Pressure and Pulse if able (but poor efficacy)
- Transfuse Packed Red Blood Cells
- pRBC transfusion indicated for severe Anemia (Hemoglobin <7 g/dl, restrictive strategy)
- pRBC transfusion Indications for Hemoglobin <8 g/dl
- Symptomatic Anemia
- Continued heavy bleeding
- Ischemic cardiovascular disease or other affected significant comorbidity
- Consider Coagulopathy management
- See Emergent Reversal of Anticoagulation
- Indicated in hemodynamic instability despite other Resuscitation
- Available agents
- Prothrombin Complex Concentrate (PCC 4)
- Fresh Frozen Plasma (FFP)
- Platelet Transfusion (for Platelet Count <30,000, or for endoscopy, 50,000)
- Tranexamic Acid (NOT recommended, lacks evidence of benefit)
- Antiplatelet agent management
- Continuing low dose Aspirin (e.g. 81 mg) has both risks and benefits
- Those with significant cardiovascular disease risk may continue Aspirin 81 mg daily
- Cardiovascular disease patients have fewer serious cardiovascular events on low dose Aspirin
- Low dose Aspirin is associated with increased risk of rebleeding after initial GI Bleeding event
- Low dose Aspirin use prior to endoscopy is associated with increased mortality in GI Bleeding
- Those with significant cardiovascular disease risk may continue Aspirin 81 mg daily
- Discontinue Dual Antiplatelet Therapy
- Continue low dose Aspirin
- Hold nonaspirin Antiplatelet Therapy for 1 to 7 days
- Continuing low dose Aspirin (e.g. 81 mg) has both risks and benefits
- Other medications to consider
- Octreotide
- Augments Platelet aggregation, decreases splanchnic perfusion and decreases Angiogenesis
- Consider in Small BowelHemorrhage and Angiodysplasia
- Octreotide
- Obtain endoscopy (Colonoscopy and possible upper endoscopy if unclear source)
- See Colonoscopy in GI Bleeding
- Obtain Colonoscopy when patient is hemodynamically stable and with adequate Colonoscopy preparation
- Preparation with Polyethylene Glycol 4 to 6 Liters over 3-4 hours until output without stool or blood
- Goal endoscopy timing is within 24 hours of significant acute Lower Gastrointestinal Bleeding
- Endoscopy is safe when INR <=2.5 and Platelet Count >50,000
- Hemostasis may be achieved with hemostatic clips, Epinephrine injections and coagulation
- Avoid tests without adequate yield in acute bleeding
- Avoid Flexible Sigmoidoscopy
- Avoid Barium Enema
- Consider Upper Gastrointestinal Bleeding source
- Upper GI Bleed with Hematochezia is always considered unstable
- BUN to Creatinine ratio increased >30-36 in Upper Gastrointestinal Bleeding (controversial reliability)
- Nasogastric lavage and aspirate is not typically recommended to differentiate source (low efficacy)
- Bleeding ceases spontaneously (occurs in 50% of cases)
- See Colonoscopy in GI Bleeding
- Evaluation may proceed outpatient in stable patient
- Colonoscopy negative: Consider Upper GI Bleed
- Brisk GI Bleeding obscures source on Colonoscopy (or too unstable for endoscopy)
- See Angiography in GI Bleeding
- CT Angiography WITHOUT Oral Contrast (preferred)
- See CT Angiography in Gastrointestinal Bleeding
- May be test of choice in heavy Lower GI Bleeding in which endoscopy cannot be performed
- May direct exploratory laparotomy (identifying source)
- Typically performed as triple phase scan (CT non-contrast, CTA arterial phase, CT venous phase)
- Percutaneous catheter arteriography and embolization
- Consider as second-line test if bleeding persists and source not identified
- Highest yield study and allows for directed embolization
- Complications include acute bowel ischemia, contrast nephropathy
- Radionuclide Red Cell Scan (Technetium Tc 99m-labeled RBC Scintigraphy)
- Less accurate, older procedure that is rarely performed now, and not typically recommended
- May be considered in hemodynamically stable patients in whom other methods are nondiagnostic
- More useful in slower bleeding (<0.4 ml/minute) but requires a minimum of 0.1 ml/min
- Immediate blush identifies high risk bleeding
- Slow continuous or recurrent bleeding
- See Colonoscopy in GI Bleeding
- No source on Colonoscopy
- Radionuclide Red Cell Scan: Positive
- See Angiography in GI Bleeding
- Consider repeat Colonoscopy in GI Bleeding
- Guided by red cell scan results
- Consider exploratory laparotomy
- See below for indications
- Radionuclide Red Cell Scan: Negative
- Consider Upper Endoscopy
- Evaluate for Hematochezia due to Upper GI Bleed
- These cases are always hemodynamically unstable
- Consider Small Intestinal Bleeding
- Consider Upper Endoscopy
- Radionuclide Red Cell Scan: Positive
- Exploratory laparotomy
- Adjunctive intraoperative measures
- Intraoperative Colonoscopy
- Intraoperative angiography
- Subtotal colectomy is a a procedure of last resort
- Indicated only in uncontrolled Massive Hemorrhage where no alternative management exists
- High morbidity and mortality associated with emergent subtotal colectomy
- Indications
- Transfusion >4 units in 24 hours
- Transfusion >10 units total
- Recurrent bleeding episodes
- Comorbid conditions significantly affected
- Adjunctive intraoperative measures
- Disposition
- Several established tools may help with risk stratification to outpatient management
- Oakland Score for Safe Discharge After Lower Gastrointestinal Bleeding
- https://www.mdcalc.com/calc/10042/oakland-score-safe-discharge-lower-gi-bleed
- Score <=8 is consistent with safe discharge and outpatient follow-up
XIV. Management: Asymptomatic mild Rectal Bleeding (clinic)
- Age over 35 years: Colonoscopy
- Age 25 to 35 years: Diagnostics based on risk factors
- Age under 25 years: Anoscopy, Flexible Sigmoidoscopy
- Lewis (2002) Ann Intern Med 136:99-110 [PubMed]
XV. Prognosis
- Overall mortality 4%
- Mortality may approach 20% if admitted for comorbidity
XVI. Resources
XVII. References
- Rodgers (2024) Crit Dec Emerg Med 38(11): 4-11
- Morris (2020) Crit Dec Emerg Med 34(8): 9
- Demarkles (1993) Med Clin North Am 77(5):1085-100 [PubMed]
- Fallah (2000) Med Clin North Am 84(5):1183-208 [PubMed]
- Hawks (2020) Am Fam Physician 101(4): 206-12 [PubMed]
- Manten (1995) Postgrad Med 97(4):154-7 [PubMed]
- Peter (1999) Emerg Med Clin North Am 17(1):239-61 [PubMed]
- Sengupta (2023) Am J Gastroenterol 118(2): 208-31 [PubMed]
- Zuckerman (2000) Gastroenterology 118:201-21 [PubMed]