Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 15-07: Gastrointestinal Bleeding + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Hematochezia usually present 10% of cases of hematochezia are due to upper gastrointestinal source Stable patients can be evaluated by colonoscopy Massive active bleeding calls for evaluation with sigmoidoscopy, upper endoscopy, angiography, or nuclear bleeding scan +++ General Considerations ++ Lower GI bleeding is defined as that arising below the ligament of Treitz, ie, small intestine or colon; up to 95% of cases derive from the colon Lower tract bleeding 33% less common than upper tract bleeding Tends to have a more benign course Is less likely to present with shock or orthostasis (< 20%) or to require transfusions (< 40%) Spontaneous cessation in > 75%; hospital mortality in < 4% Most common causes in patients age < 50 years Infectious colitis Anorectal disease Inflammatory bowel disease Most common causes in patients age > 50 years Diverticulosis (over 50% of cases) Angioectasias (5%) Neoplasms (polyps or carcinoma) (7%) Ischemia Radiation-induced proctitis Solitary rectal ulcer Nonsteroidal anti-inflammatory drug (NSAID)-induced ulcers Small bowel diverticula Colonic varices Risk of lower GI bleeding is increased in patients taking Aspirin Nonaspirin antiplatelet agents Nonsteroidal anti-inflammatory drugs (NSAIDs) Diverticular bleeding Acute, painless, large-volume maroon or bright red hematochezia occurs in 3–5% of patients with diverticulosis, often associated with the use of NSAIDs Bleeding more commonly originates on the right side > 95% require less than 4 units of blood transfusion Bleeding subsides spontaneously in 80% of patients but may recur in up to 25% Angioectasias Painless bleeding ranging from occult blood loss to melena or hematochezia Bleeding most commonly originates in the cecum and ascending colon Causes: congenital; hereditary hemorrhagic telangiectasia; autoimmune disorders, typically scleroderma Neoplasms: benign polyps and carcinoma cause chronic occult blood loss or intermittent anorectal hematochezia Anorectal disease Small amounts of bright red blood noted on the toilet paper, streaking of the stool, or dripping into the toilet bowl Clinically significant blood loss can sometimes occur Ischemic colitis Hematochezia or bloody diarrhea associated with mild cramps In most cases, bleeding is mild and self-limited +++ Demographics ++ Diverticular bleeding is more common in patients age > 50 years Angiodysplasia bleeding is more common in patients age > 70 years and in those with chronic kidney disease Ischemic colitis is most commonly seen In older patients due to atherosclerotic disease—postoperatively, after ileoaortic or abdominal aortic aneurysm surgery In younger patients due to vasculitis, coagulation disorders, estrogen therapy, and long-distance running + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Brown stools mixed or streaked with blood suggest rectosigmoid or anal source Painless large-volume bleeding suggests diverticular bleeding Maroon stools suggest a right colon or small intestine source Black stools (melena) suggest a source proximal to the ligament of Treitz, but dark maroon stools arising from small intestine or right colon may be misinterpreted as "melena" Bright red blood per rectum occurs uncommonly with upper tract bleeding and almost always in the setting of massive hemorrhage with shock Bloody diarrhea associated with cramping abdominal pain, urgency, or tenesmus suggests inflammatory bowel disease (especially ulcerative colitis), infectious colitis, or ischemic colitis +++ Differential Diagnosis ++ Diverticulosis Angioectasias, eg, idiopathic arteriovenous malformation, CREST syndrome, hereditary hemorrhagic telangiectasias Colonic polyps Colorectal cancer Inflammatory bowel disease Hemorrhoids Anal fissure Ischemic colitis Infectious colitis Radiation colitis or proctitis NSAID-induced ulcers of small bowel or right colon + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ Complete blood count, including platelet count Prothrombin time/INR Serum creatinine, blood urea nitrogen Type and cross-match +++ Imaging Studies ++ In most settings, multidetector CT angiography is preferred to technetium-labeled red blood cell scanning to detect active arterial bleeding and to help localize bleeding to the small intestine, right colon, or left colon Urgent angiography Performed if scintigraphy or CT angiography demonstrates active bleeding in an attempt to localize the bleeding site and make embolization therapy possible May be performed without first attempting a scintigraphy or CT angiography in patients with massive lower gastrointestinal bleeding and continued hemodynamic instability +++ Diagnostic Procedures ++ Nasogastric tube aspiration to exclude upper tract source Anoscopy Colonoscopy Preferred initial study in most cases of acute, large-volume bleeding requiring hospitalization However, the timing of this procedure is controversial One trial compared colonoscopy within 24 hours versus elective colonoscopy Colonoscopy within 24 hours did not reduce length of stay, rebleeding, or mortality Thus, patients with stable vital signs and whose lower gastrointestinal bleeding appears to have stopped, colonoscopy can be performed electively within 24–36 hours of admission after appropriate resuscitation and bowel cleansing Small intestine push enteroscopy or video capsule imaging in patients with unexplained recurrent hemorrhage of obscure origin, suspected from the small intestine Upper endoscopy in massive hemotochezia to exclude upper GI source + Treatment Download Section PDF Listen +++ +++ Surgery ++ Surgery indicated in patients with ongoing bleeding that requires > 6 units of blood transfusion within 24 hours or > 10 total units and in whom endoscopic or angiographic therapy failed Limited resection of the bleeding segment of small intestine or colon, if possible Total abdominal colectomy with ileorectal anastomosis, if bleeding site cannot be precisely identified +++ Therapeutic Procedures ++ Therapeutic colonoscopy: high-risk lesions (eg, diverticulum with active bleeding or a visible vessel, or an angioectasia) can be treated endoscopically with saline or epinephrine injection, cautery (bipolar or heater probe), application of metallic clips or bands, and application of a hemostatic powder (TC-325) Angiography with selective embolization achieves immediate hemostasis in more than 95% of patients when a bleeding lesion is identified + Outcome Download Section PDF Listen +++ +++ Complications ++ Major complications from intra-arterial embolization (mainly ischemic colitis) occur in 5% of patients; rebleeding occurs in up to 25% +++ Prognosis ++ 25% of patients with diverticular hemorrhage have recurrent bleeding +++ When to Admit ++ All patients with significant hematochezia + References Download Section PDF Listen +++ + +Almadi MA et al. Patient presentation, risk stratification, and initial management in acute lower gastrointestinal bleeding. Gastrointest Endosc Clin N Am. 2018 Jul;28(3):363–77. [PubMed: 29933781] + +Becq A et al. Hemorrhagic angiodysplasia of the digestive tract: pathogenesis, diagnosis, and management. Gastrointest Endosc. 2017 Nov 86(5):792–806. [PubMed: 28554655] + +Hookey L et al. Successful hemostasis of active lower GI bleeding using a hemostatic powder as monotherapy, combination therapy, or rescue therapy. Gastrointest Endosc. 2019 Apr;89(4):865–71. [PubMed: 30612959] + +Lee JK et al. ASGE guideline on the role of endoscopy for bleeding from chronic radiation proctopathy. Gastrointest Endosc. 2019 Aug;90(2):171–82. [PubMed: 31235260] + +Nigam N et al. Early colonoscopy for diverticular bleeding does not reduce risk of postdischarge recurrent bleeding: a propensity score matching analysis. Clin Gastroenterol Hepatol. 2019 May;17(6):1105–11. [PubMed: 30296595] + +Niikura R et al. Efficacy and safety of early vs elective colonoscopy for acute lower gastrointestinal bleeding. Gastroenterology. 2020 Jan;158(1):168–75. [PubMed: 31563627] + +Oakland K et al. Rebleeding and mortality after lower gastrointestinal bleeding in patients taking antiplatelets or anticoagulants. Clin Gastroenterol Hepatol. 2019 Jun;17(7):1276–84. [PubMed: 29277620] + +Soetikno R et al. The role of endoscopic hemostasis therapy in acute lower gastrointestinal hemorrhage. Gastrointest Endosc Clin N Am. 2018 Jul;28(3):391–408. [PubMed: 29933783]