Small amount of bleeding in the lower gastrointestinal tract

Introduction Lower gastrointestinal bleeding refers to the intestines less than 50cm from the duodenal suspensory ligament, including jejunum, ileum, colon and rectal lesions. It is customary not to include hemorrhage caused by sputum and anal fissure. Blood is the main type, and the light is only fecal occult blood or black feces. When the amount of bleeding is large, blood is discharged, and in severe cases, shock occurs. Clinical manifestations: a large number of digestive tract bleeding, dizziness, palpitations, nausea, thirst, black sputum or syncope; skin gray and cold due to vasoconstriction and insufficient blood perfusion; pale after pressing the nail bed, and recovered after a long time. Poor vein filling, body surface veins often collapse. The patient feels tired and weak, and can be further apathetic, restless, even unresponsive, and confused. Hemorrhage and black feces occur in a large amount of bleeding in the upper digestive tract. Most of the lower massive digestive tract bleeding is characterized by hematemesis; chronic small amount of bleeding is positive for fecal occult blood. (1) Factors that cause bleeding and affect hemostasis 1, mechanical damage: such as foreign body damage to the esophagus, drug tablets on the vault veins, severe vomiting caused by esophageal cardia mucosal tear. 2, the role of gastric acid or other chemical factors: the latter such as the intake of acid and alkali corrosive agents, acid and alkaline drugs. 3, mucosal protection and repair function decline: aspirin, non-steroidal anti-inflammatory drugs, steroid hormones, infection, stress, etc. can make the protection and repair function of the digestive tract mucosa damaged. 4, vascular destruction: inflammation, ulcers, malignant tumors, etc. can destroy arteriovenous blood vessels, causing bleeding. 5, local or systemic coagulopathy: the acidic environment of gastric juice is not conducive to platelet aggregation and clot formation, anticoagulant drugs, systemic bleeding disease or coagulopathy disease can easily cause bleeding in the digestive tract and other parts of the body. (B) pathophysiological changes after hemorrhage 1, the reduction of circulating blood volume: the elderly have more arteriosclerosis of the heart, brain, kidney and other important organs, less severe circulating blood volume can cause obvious ischemic manifestations of these important organs, and even aggravate the original underlying diseases, causing One or more important organs are abnormally functional or even depleted, and a large amount of bleeding is more likely to cause peripheral failure and multiple organ failure. 2. Absorption of blood protein breakdown products: Nitrogenemia can be caused by intestinal absorption of nitrogen-containing decomposition products. In the past, it was thought that the absorption of blood decomposition products could cause "absorption of heat". It is believed that the fever after gastrointestinal hemorrhage is related to the reduction of circulating blood volume caused by thermoregulatory central dysfunction. 3, the body's compensation and repair (1) Circulatory system: heart rate is increased, and peripheral circulation resistance is increased to maintain blood perfusion of vital organs. (2) Endocrine system: Increased secretion of aldosterone and vasopressin reduces water loss to maintain blood volume. (3) Hematopoietic system: bone marrow hematopoiesis is active, reticulocytes are increased, and the amount of red blood cells and hemoglobin is gradually restored.

Cause

(A) common causes: the cause of upper gastrointestinal bleeding in the elderly with gastric ulcer, cardia tear, gastritis, esophagitis, cancer, biliary bleeding, pancreatic origin. Among them, 40% of patients with digestive tract ulcers and bleeding. Among the causes of lower gastrointestinal bleeding, cancer is common in cancer, diverticulum, and ischemic colitis, of which 50% are caused by colonic diverticulitis in the elderly over 80 years old.

1. Gastric ulcer "Peptic ulcer is the primary cause of upper gastrointestinal bleeding. It is more common in elderly patients with gastric ulcer, and the effect of conservative treatment of gastric ulcer is better than that of duodenal ulcer. The prevalence of gastric ulcer in the elderly. High may be related to the following factors: 1 gastric vascular sclerosis and gastric mucosal atrophy lead to impaired gastric mucosal barrier function. 2 slower gastric motility, longer retention of gastric contents, 3 pyloric sphincter aging, can not effectively prevent bile and intestinal reflux .

2, acute gastric mucosal lesions "old people due to gastric mucosal barrier function and gastric submucosal vascular sclerosis, prone to gastric mucosal erosion, bleeding, acute superficial ulcer formation characterized by acute gastric mucosal lesions. In elderly patients Drugs are the most common cause of this disease, including anticoagulants, non-steroidal anti-inflammatory drugs, prednisone. Even with low-dose (50mg / d) enteric-coated aspirin, 43-482d (average 171 d Upper gastrointestinal bleeding can also occur after the upper gastrointestinal bleeding, therefore, elderly patients with cardio-ischemic diseases such as peptic ulcer and other diseases, long-term application of low-dose enteric-coated aspirin as an anticoagulant drug. Diseases such as infection, shock, burns, intracranial lesions, respiratory failure, and uremia are also common causes of acute gastric mucosal lesions.

3, malignant tumors: in the elderly upper gastrointestinal bleeding, malignant tumors accounted for 25%, the most common gastric cancer, followed by esophageal cancer, rectal cancer, colon cancer. It has been reported that in 600 elderly patients with gastric cancer, the dominant blood loss is 30.5%, and the large amount of bleeding accounts for 38.8%, which is different from the traditional view that gastric cancer is a sustained small amount of bleeding.

4, esophagogastric varices rupture: the upper gastrointestinal bleeding caused by esophageal rupture in the elderly accounted for only 6.2% - 11.5%, significantly lower than young and middle-aged patients (16% -34%). It is worth noting that upper gastrointestinal bleeding in 1/3 patients with esophageal varices is caused by coexisting digestive ulcers or gastric mucosal lesions, rather than varicose veins.

5, Dieulafoy disease: also known as gastric submucosal constant diameter arterial bleeding, is a unique disease of the elderly, is also one of the causes of acute upper gastrointestinal bleeding in the elderly, the average age of onset is 64 years old, the mortality rate of 23% is recently highly valued One of the senile diseases. The disease occurs in the 6cm of the small esophagus and stomach junction of the gastric cardia, occasionally in the duodenum, jejunum and descending colon. The lesion is small and can be smashed to 2-5 mm. The central artery with a diameter of 1-3 mm can be seen as a jet-like hemorrhage. It can be rich in blood clots, such as no bleeding, no gastroscopy or surgery. The pathogenesis is unknown. Some scholars believe that the congenital dysplasia of the submucosal artery is accompanied by different degrees of arteriosclerosis. Others believe that the microscopic focal defect or erosion of the gastric mucosa involves the rupture of the constant diameter artery. Unexplained acute upper gastrointestinal bleeding, especially arterial bleeding, should be highly suspected. The diagnosis is mainly based on gastroscope, but the detection rate is only 37%. It can be seen under the microscope:

1 jet bleeding in the gastric cardia area.

2 Small lesions of the gastric mucosa are difficult to find because they are covered by blood.

3 Occasionally, the central pulsatile arterioles of the lesion are visible. Surgical surgery is the first choice for the treatment of this disease, but it is not possible to blindly explore or perform most of the resection of the stomach to prevent missing hemorrhage in the cardia, resulting in postoperative bleeding. If there are no surgical conditions, try sclerotherapy or electrocoagulation.

6, colonic diverticulitis: with age, colonic and ring muscle thickening, elderly constipation increased intestinal pressure, can induce colonic diverticulitis. Most patients can be asymptomatic, <5% have a little abdominal pain, and blood in the stool may be the only feature. Moreover, it can be confirmed by further examination from the positive fecal occult blood test. Hemorrhage was seen in the left colon and sigmoid colon by fiberoptic colonoscopy.

7, other: chronic colitis, intestinal polyps or polyposis, intestinal vascular malformations, fistula or anal fissure are also common causes of lower gastrointestinal bleeding.

(2) Other causes

1, esophagus: reflux esophagitis, esophageal hiatal hernia, esophageal diverticulitis, esophageal foreign body damage, esophageal radiation damage.

2, stomach: chronic gastritis, gastric mucosal prolapse, post-surgical lesions (bile reflux anastomosis and residual gastritis, recurrent peptic ulcer, residual gastric cancer, etc.), other gastric tumors (leiomyomas, leiomyosarcoma, Lymphoma, neurofibromatosis, gastric polyps, etc.) and gastric vascular changes (vasodilation of the antrum, gastroduodenal arteriovenous malformations, etc.).

3, duodenum: duodenitis, hookworm disease, duodenal diverticulitis.

4, hepatobiliary gland: biliary calculi, biliary ascariasis, gallbladder or cholangiocarcinoma, liver cancer, pancreatic cancer, acute pancreatitis.

5, small intestine: acute hemorrhagic necrotic enteritis, ischemic bowel disease.

6, colon: radiation enteritis, toxic enteritis, other tumors (sarcoma, lymphoma, leiomyoma, lipoma, etc.) and vascular lesions (mesenteric vascular embolism, hemangioma, vascular dysplasia, etc.) intussusception, intestinal torsion, etc. .

7, rectum and anal canal: trauma, ulcers, idiopathic ulcerative proctitis, rectal carcinoid.

8. Systemic diseases: severe infection, cerebrovascular accident, uremia, disseminated intravascular coagulation, certain blood diseases, connective tissue diseases, infectious diseases (epidemic hemorrhagic fever, gastrointestinal tuberculosis, etc.) and acute stress Status (burn, foreign, major surgery, shock, hypoxia, heart failure, etc.).

an examination

Related inspection

Dung triceps urinary total auris colonoscopy double balloon enteroscopy

Most of the lower gastrointestinal bleeding is caused by the digestive tract disease itself. A few cases may be local bleeding of systemic diseases, so medical history and physical examination are still necessary diagnostic steps. In general, the higher the bleeding site, the darker the color of the blood in the stool; the lower the bleeding site, the brighter the blood of the blood in the stool, or the blood. This of course depends on the speed and number of bleeding, such as the speed of bleeding and the large amount of bleeding, the time the blood stays in the digestive tract is short, even if the bleeding site is higher, the blood in the stool may be bright red. Careful collection of medical history and positive signs is very helpful in judging the cause of bleeding. For example, blood drops after defecation, and is not mixed with feces in guinea, anal fissure or rectal polyps; moderate amount of blood in the stool is more common in mesenteric and portal vein thrombosis. Formation, acute hemorrhagic necrotic enteritis, ileal colon diverticulum and ischemic colitis, and even upper gastrointestinal lesions can also be manifested as a large amount of blood in the stool, which is differentiated at the time of diagnosis.

Blood and feces mixed, with mucus, should consider colon cancer, colon polyposis, chronic ulcerative colitis; stool is pus-like blood or bloody stool with mucus and pus, should consider bacillary dysentery, colonic schistosomiasis, chronic colon Inflammation, colon tuberculosis, etc.; blood in the stool with severe abdominal pain, and even shock phenomenon, should consider mesenteric vascular embolism, hemorrhagic necrotic enteritis, ischemic colitis, intussusception, etc.; blood in the stool with abdominal mass, should consider colon Cancer, intussusception, etc. Blood in the stool with signs of bleeding on the skin or other organs should pay attention to blood system diseases, acute infectious diseases, severe liver disease, uremia, vitamin C deficiency and so on. However, in actual work, it is often difficult to diagnose clinically. The following tests are required:

(1) Stomach tube attraction: If there is no blood in the extracted gastric juice and there is bile, it is certain that the bleeding comes from the lower digestive tract.

(B) hard tube sigmoidoscopy: can directly peek into the rectum and sigmoid lesions, Hunt statistics 55% colon cancer and 4.7 ~ 9.7% adenomatous polyps can be found by rigid sigmoidoscopy.

(C) fiber colonoscopy: endoscopy has been widely used in the diagnosis of intestinal bleeding, with the advantages of direct vision, and can be used for biopsy and small polypectomy during the examination, but also can be found in mild inflammation Sexual lesions and superficial ulcers. This test can still be performed during acute bleeding, but in cases of severe bleeding with shock, it should be postponed until the condition is stable. The chance of a false positive in endoscopy is much less than that of double contrast. The Department of Radiology of Huashan Hospital of Shanghai Medical University used to compare the endoscopic and colon double contrast angiography with surgery and pathological examination in 115 cases of blood in the stool. The total diagnostic coincidence rate of endoscopic and double contrast angiography was 93.9% and 86.1%, respectively. However, the diagnostic coincidence rates for colon tumors and polyps were 94.9% and 93.2%, respectively. Most cases of missed diagnosis of colon double contrast examination were superficial mucosal and submucosal lesions, indicating the diagnosis of superficial inflammatory lesions by endoscopy. Better than double contrast angiography. However, endoscopy can not completely replace barium enema examination, especially double contrast examination of the colon, because endoscopy also has its limited aspects, such as colonoscopy sometimes can not fully reach the ileocecal area, there are also blind spots in observation, in Tumors and inflammation caused intestinal stenosis caused by colonoscopy, 9 of the 115 patients in this group caused colonoscopy incomplete or failed, accounting for 7.8%; foreign literature reported that colonoscopy can not reach the ileocecal Up to 20%. Therefore, endoscopy and double contrast angiography can complement each other.

(4) Double contrast angiography of barium enema and colon: barium enema can not show microscopic lesions in the colon. For example, after injecting tincture, inject gas from the anal canal through the balloon about 1,000ml, and observe the expansion of the intestinal tract under fluoroscopy. The anal canal was removed, and the patient was turned 360° several times to make the colon form a good double contrast development. The method of segmental radiography, including rectal lateral position, sigmoid supine, prone and oblique position, general video 10-15 Zhang, in addition to showing the contour of the lesion, can also observe the functional changes of the colon, which is not observed by endoscopy.

(5) Selective angiography: It has been widely used in the examination of gastrointestinal bleeding in recent years. In 1963, Nusbaum confirmed in the canine experiment that the contrast hemorrhage can be detected by selective mesenteric artery or celiac artery angiography when the intestinal bleeding rate reaches 0.5 ml/min. In 1989, the Department of Radiology of Huashan Hospital of Shanghai Medical University in 22 experiments. In the middle, it was shown that the bleeding from the arteries could only be seen when the rate reached 1 ml min. In 27 patients with lower gastrointestinal bleeding, 24 patients with abnormal angiography showed abnormal findings, and 15 of them showed bleeding site angiography. In the case of spillover, 9 cases showed abnormal vascular changes, and the remaining 3 cases were false negatives, and the diagnostic coincidence rate was 88.9%. However, selective angiography must be performed through the operation of the femoral artery cannula, which is a damage test and is a disadvantage.

For the diagnosis of acute lower gastrointestinal hemorrhage, fiber colonoscopy should be performed first, and double contrast examination of barium enema and colon is only applicable to cases where bleeding has stopped. However, in the case of acute massive bleeding, especially in the large amount of blood in the intestinal lumen, endoscopy is often limited, and the colonoscopy is difficult to reach the small intestine, and the bleeding lesion of the small intestine cannot be detected. Although radionuclide imaging is highly sensitive to intestinal bleeding, its specificity is too poor, and the bleeding site shown is often uncertain, so the practical value is not large. Where barium enema, double contrast angiography, and endoscopy fail to identify the cause of lower gastrointestinal bleeding, especially in acute massive intestinal bleeding and intestinal vascular malformations, vascular dysplasia, etc., selective angiography has its fingers Invasion, and in some cases, interventional radiology can also be performed.

Differential diagnosis

Upper gastrointestinal bleeding: from the esophagus to the rectum called the digestive tract of the human body. The boundary between the duodenum and the jejunum is bounded by the upper digestive tract and the lower digestive tract below. Therefore, the upper digestive tract should include esophageal, gastric, duodenal and pancreatic, biliary bleeding, collectively referred to as upper gastrointestinal bleeding. Among them, ulcer disease accounts for about half, and esophageal and gastric varices account for 25%. In recent years, cases of acute hemorrhagic gastritis and erosive gastritis with blood have also increased, and about 5% of cases have not been confirmed, even if The laparotomy failed to find the cause of the bleeding. Its clinical manifestations are mainly hematemesis and black feces, often accompanied by clinical manifestations of hypovolemia, which is a common emergency.

Gastrointestinal bleeding: Many lesions in the digestive tract can bleed, but most can be explained by a few disease diagnoses. The difference between upper and lower gastrointestinal bleeding depends on its proximal or distal end of the Treitz ligament.

Vaginal bleeding: a common symptom of female genital diseases. Bleeding can come from the vulva, vagina, cervix and endometrium, but it is most common in the uterus. Although the amount of vaginal bleeding can be life-threatening, but the cause of good disease, the prognosis is good; and the amount of bleeding is also the earliest symptoms of malignant tumors, such as neglect and delay treatment, causing adverse consequences.

Most of the lower gastrointestinal bleeding is caused by the digestive tract disease itself. A few cases may be local bleeding of systemic diseases, so medical history and physical examination are still necessary diagnostic steps. In general, the higher the bleeding site, the darker the color of the blood in the stool; the lower the bleeding site, the brighter the blood of the blood in the stool, or the blood. This of course depends on the speed and number of bleeding, such as the speed of bleeding and the large amount of bleeding, the time the blood stays in the digestive tract is short, even if the bleeding site is higher, the blood in the stool may be bright red. Careful collection of medical history and positive signs is very helpful in judging the cause of bleeding. For example, blood drops after defecation, and is not mixed with feces in guinea, anal fissure or rectal polyps; moderate amount of blood in the stool is more common in mesenteric and portal vein thrombosis. Formation, acute hemorrhagic necrotic enteritis, ileal colon diverticulum and ischemic colitis, and even upper gastrointestinal lesions can also be manifested as a large amount of blood in the stool, which is differentiated at the time of diagnosis.

Blood and feces mixed, with mucus, should consider colon cancer, colon polyposis, chronic ulcerative colitis; stool is pus-like blood or bloody stool with mucus and pus, should consider bacillary dysentery, colonic schistosomiasis, chronic colon Inflammation, colon tuberculosis, etc.; blood in the stool with severe abdominal pain, and even shock phenomenon, should consider mesenteric vascular embolism, hemorrhagic necrotic enteritis, ischemic colitis, intussusception, etc.; blood in the stool with abdominal mass, should consider colon Cancer, intussusception, etc. Blood in the stool with signs of bleeding on the skin or other organs should pay attention to blood system diseases, acute infectious diseases, severe liver disease, uremia, vitamin C deficiency and so on. However, in actual work, it is often difficult to diagnose clinically. The following tests are required:

(1) Stomach tube attraction: If there is no blood in the extracted gastric juice and there is bile, it is certain that the bleeding comes from the lower digestive tract.

(B) hard tube sigmoidoscopy: can directly peek into the rectum and sigmoid lesions, Hunt statistics 55% colon cancer and 4.7 ~ 9.7% adenomatous polyps can be found by rigid sigmoidoscopy.

(C) fiber colonoscopy: endoscopy has been widely used in the diagnosis of intestinal bleeding, with the advantages of direct vision, and can be used for biopsy and small polypectomy during the examination, but also can be found in mild inflammation Sexual lesions and superficial ulcers. This test can still be performed during acute bleeding, but in cases of severe bleeding with shock, it should be postponed until the condition is stable. The chance of a false positive in endoscopy is much less than that of double contrast. Endoscopic and colon double contrast angiography was compared with surgery and pathology in 115 cases of blood in the stool. The total diagnostic coincidence rates of endoscopic and double contrast angiography were 93.9% and 86.1%, respectively, but the diagnosis of colon tumors and polyps. The coincidence rates were 94.9% and 93.2%, respectively. Most cases of missed diagnosis of colon double contrast examination were superficial mucosal and submucosal lesions, indicating that endoscopic examination is superior to double contrast angiography in the diagnosis of superficial inflammatory lesions. However, endoscopy can not completely replace barium enema examination, especially double contrast examination of the colon, because endoscopy also has its limited aspects, such as colonoscopy sometimes can not fully reach the ileocecal area, there are also blind spots in observation, in Tumors and inflammation caused intestinal stenosis caused by colonoscopy, 9 of the 115 patients in this group caused colonoscopy incomplete or failed, accounting for 7.8%; foreign literature reported that colonoscopy can not reach the ileocecal Up to 20%. Therefore, endoscopy and double contrast angiography can complement each other.

(4) Double contrast angiography of barium enema and colon: barium enema can not show microscopic lesions in the colon. For example, after injecting tincture, inject gas from the anal canal through the balloon about 1,000ml, and observe the expansion of the intestinal tract under fluoroscopy. The anal canal was removed, and the patient was turned 360° several times to make the colon form a good double contrast development. The method of segmental radiography, including rectal lateral position, sigmoid supine, prone and oblique position, general video 10-15 Zhang, in addition to showing the contour of the lesion, can also observe the functional changes of the colon, which is not observed by endoscopy.

(5) Selective angiography: It has been widely used in the examination of gastrointestinal bleeding in recent years. In 1963, Nusbaum confirmed in the canine experiment that the contrast hemorrhage can be detected by selective mesenteric artery or celiac artery angiography when the intestinal bleeding rate reaches 0.5 ml/min. In 1989, the Department of Radiology of Huashan Hospital of Shanghai Medical University in 22 experiments. In the middle, it was shown that the bleeding from the arteries could only be seen when the rate reached 1 ml min. In 27 patients with lower gastrointestinal bleeding, 24 patients with abnormal angiography showed abnormal findings, and 15 of them showed bleeding site angiography. In the case of spillover, 9 cases showed abnormal vascular changes, and the remaining 3 cases were false negatives, and the diagnostic coincidence rate was 88.9%. However, selective angiography must be performed through the operation of the femoral artery cannula, which is a damage test and is a disadvantage.

For the diagnosis of acute lower gastrointestinal hemorrhage, fiber colonoscopy should be performed first, and double contrast examination of barium enema and colon is only applicable to cases where bleeding has stopped. However, in the case of acute massive bleeding, especially in the large amount of blood in the intestinal lumen, endoscopy is often limited, and colonoscopy is difficult to reach the small intestine.

It is impossible to detect bleeding lesions in the small intestine. Although radionuclide imaging is highly sensitive to intestinal bleeding, its specificity is too poor, and the bleeding site shown is often uncertain, so the practical value is not large. Where barium enema, double contrast angiography, and endoscopy fail to identify the cause of lower gastrointestinal bleeding, especially in acute massive intestinal bleeding and intestinal vascular malformations, vascular dysplasia, etc., selective angiography has its fingers Invasion, and in some cases, interventional radiology can also be performed.

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