gastrointestinal disorders
Overview of Gastrointestinal Bleeding
Evaluation of GI Bleeding
In acutely ill patients, stabilization with airway management, IV fluids, or transfusions is essential before and during diagnostic evaluation. History of present illnessshould attempt to ascertain quantity and frequency of blood passage. However, quantity can be difficult to assess because even small amounts (5 to 10 mL) of blood turn water in a toilet bowl an opaque red, and modest amounts of vomited blood appear huge to an anxious patient. However, most can distinguish between blood streaks, a few teaspoons, and clots. Patients with hematemesis should be asked whether blood was passed with initial vomiting or only after an initial (or several) nonbloody emesis. In addition, the clinician should ask specific questions to distinguish between hematemesis and hemoptysis because patients may confuse the two symptoms. Patients with rectal bleeding should be asked whether pure blood was passed; whether it was mixed with stool, pus, or mucus; or whether blood simply coated the stool or toilet paper. Those with bloody diarrhea should be asked about travel or other possible exposure to GI pathogens. Review of symptomsshould include presence of abdominal discomfort, weight loss, easy bleeding or bruising, previous colonoscopy or endoscopy results, and symptoms of anemia (eg, weakness, easy fatigability, dizziness). Past medical historyshould inquire about previous GI bleeding (diagnosed or undiagnosed); known inflammatory bowel disease, bleeding diatheses, and liver disease; and use of any medications or drugs that increase the likelihood of bleeding or chronic liver disease (eg, alcohol). General examination is focused on vital signs and other indicators of Shock (eg, tachycardia, tachypnea, pallor, diaphoresis, oliguria, confusion) and anemia (eg, pallor, diaphoresis). Patients with lesser degrees of bleeding may simply have mild tachycardia (heart rate Orthostatic changes in pulse (a change of>10 beats/minute) or blood pressure (a drop of≥10 mm Hg) often develop after acute loss of≥2 units of blood. However, orthostatic measurements are unwise in patients with severe bleeding because they can possibly cause syncope and they generally lack sensitivity and specificity as a measure of intravascular volume, especially in older adults. External stigmata of bleeding disorders (eg, petechiae, ecchymoses) are sought, as are signs of chronic liver disease (eg, spider angiomas, ascites, palmar erythema) and portal hypertension (eg, splenomegaly, dilated abdominal wall veins). A digital rectal examination is necessary to search for stool color, masses, and fissures. Anoscopy is done to diagnose hemorrhoids. Chemical testing of a stool specimen for occult blood completes the examination if gross blood is not present. Several findings suggest hypovolemia or hemorrhagic shock: Syncope Hypotension Pallor Diaphoresis Tachycardia Oliguria The history and physical examination suggest a source of bleeding in about 50% of patients, but findings are rarely diagnostic, and confirmatory testing is required. Epigastric abdominal discomfort relieved by food or antacids suggests Peptic Ulcer Disease . However, many patients with bleeding ulcers have no history of pain. Weight loss and anorexia, with or without a change in stool, suggest a GI cancer. A history of cirrhosis or chronic hepatitis suggests Varices . A history of bleeding (eg, purpura, ecchymosis, hematuria) may indicate a Overview of Coagulation Disorders (eg, hemophilia, hepatic failure). Bloody diarrhea, fever, and abdominal pain suggest Ischemic Colitis , Hematochezia suggests Colonic Diverticulosis or Blood in the nose or trickling down the pharynx suggests the nasopharynx as the source. Spider angiomas, hepatosplenomegaly, or ascites is consistent with chronic liver disease and hence possible esophageal varices. Arteriovenous malformations, especially of the mucous membranes, suggest Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber syndrome). Cutaneous nail bed and GI telangiectasia may indicate Several tests are done to help confirm the suspected diagnosis: Complete blood count (CBC), coagulation profile, and often other laboratory studies Nasogastric tube (NGT) for all but those with minimal rectal bleeding Upper endoscopy for suspected upper GI bleeding Colonoscopy for lower GI bleeding (unless clearly caused by hemorrhoids) Sometimes angiography for upper and lower GI bleeding CBCshould be obtained in patients with large-volume or occult blood loss. Patients with more significant bleeding also require coagulation studies (eg, platelet count, prothrombin time [PT], partial thromboplastin time [PTT]) and liver tests (eg, bilirubin, alkaline phosphatase,albumin, aspartate aminotransferase [AST], alanine aminotransferase [ALT]). Type and cross-match are done if bleeding is ongoing. Hemoglobin and hematocrit may be repeated up to every 6 hours in patients with severe bleeding. Nasogastric aspiration and lavageshould be done in all patients with suspected upper GI bleeding (eg, hematemesis, coffee-ground emesis, melena, massive rectal bleeding). Bloody nasogastric aspirate indicates active upper GI bleeding, but about 10% of patients with upper GI bleeding have no blood in the nasogastric aspirate. Coffee-ground material indicates bleeding that is slow or stopped. If there is no sign of bleeding, and bile is returned, the NGT is removed; otherwise, it is left in place to monitor continuing or recurrent bleeding. Nonbloody, nonbilious return is considered a nondiagnostic aspirate. Upper endoscopy(examination of the esophagus, stomach, and duodenum) should be done for upper GI bleeding. Because endoscopy may be therapeutic as well as diagnostic, it should be done rapidly for significant bleeding but may be deferred for 24 hours if bleeding stops or is minimal. Upper GI barium x-rays have no role in acute bleeding, and the contrast used may obscure subsequent attempts at angiography. Flexible sigmoidoscopy and anoscopymay be all that is required acutely for patients with symptoms typical of hemorrhoidal bleeding. All other patients with hematochezia should havecolonoscopy,which can be done electively after routine preparation unless there is significant ongoing bleeding. In such patients, a rapid prep (5 to 6 L ofpolyethylene glycolsolution delivered via NGT or by mouth over 3 to 4 hours) often allows adequate visualization. Angiographymay be used to localize the source if it cannot be visualized with colonoscopy and ongoing bleeding is sufficiently rapid (>0.5 to 1 mL/minute). Some angiographers first take a radionuclide scan to focus the examination, because angiography is less sensitive than the radionuclide scan. Angiography is useful in the diagnosis of upper as well as lower GI bleeding and permits certain therapeutic maneuvers (eg, embolization, vasoconstrictor infusion). The American Journal of Gastroenterology’s2023 updated guidelines on management of patients with acute lower GI bleedingsuggest CT angiography as the initial diagnostic test in patients with ongoing hemodynamically significant hematochezia. The decision of whether to proceed with endoscopy or angiography as the initial diagnostic or therapeutic test should be based on the patient's clinical status and on the expertise and infrastructure available at the treating hospital. Diagnosis of occult bleeding can be difficult, because heme-positive stools may result from bleeding anywhere in the GI tract. Endoscopy is the preferred method, with symptoms determining whether the upper or lower GI tract is examined first. Double-contrast barium enema and sigmoidoscopy can be used for the lower tract when colonoscopy is unavailable or the patient refuses it. If the results of upper endoscopy and colonoscopy are negative and occult blood persists in the stool, an upper GI series with small-bowel follow-through, CT enterography, small-bowel endoscopy (enteroscopy), capsule endoscopy (which uses a small pill-like camera that is swallowed), technetium-labeled colloid or red blood cell (RBC) scan, and angiography should be considered. Capsule endoscopy is of limited value in an actively bleeding patient. 