Blood in stool

Introduction Blood in the stool refers to a kind of digestive tract symptom in which the blood is discharged from the anus, the stool is bloody, or all is bloody, and the color is bright red, dark red or tar. Blood in the stool is generally seen in the lower gastrointestinal bleeding, especially in the colon and rectum, but occasionally upper gastrointestinal bleeding can be seen. The color of blood in the stool depends on the location of the gastrointestinal bleeding, the amount of bleeding, and the time the blood stays in the intestine. Blood in the stool, accompanied by bleeding from the skin or other organs, is more common in blood system diseases and other systemic diseases. Such as leukemia, diffuse intravascular coagulation and so on.

Cause

Cause

First, lower gastrointestinal diseases

(a) anal canal disease

Common in sputum, anal fissure, anal thin.

(two) rectal diseases

1, rectal inflammatory diseases: bacterial dysentery, ulcerative colorectal inflammation, rectal tuberculosis.

2, rectal tumor: rectal polyps, rectal papilloma. Rectal cancer, rectal carcinoid, adjacent malignant tumor invading the rectum.

3, rectal injury: radiation proctitis, foreign body, device examination or biopsy caused by injury and bleeding.

(three) colon disease

1, inflammatory lesions: acute bacterial dysentery, amoebic bowel disease, ulcerative colitis, intestinal tuberculosis, colon Crohn's disease, Civentricular inflammation and Ci room ulcer.

2, tumor: colon cancer, colon polyposis.

(4) Small bowel disease

1, inflammatory lesions: acute hemorrhagic necrotic enteritis, Civentricular inflammation and Ci room ulcer Crohn disease, intestinal tuberculosis, intestinal typhoid.

2, tumor: malignant lymphoma, leiomyosarcoma, small intestine carcinoid, cancer, fibrosarcoma, neurofibrosarcoma. Leiomyoma. Lipoma, adenoma, fibroid, hemangioma.

Second, lower gastrointestinal vascular disease

Ischemic bowel disease is common in mesenteric arterial embolism or thrombosis, mesenteric venous thrombosis, venous thrombosis, intussusception, intestinal torsion, vascular malformation, and the like.

Third, systemic diseases

1, acute infectious diseases: epidemic hemorrhagic fever, leptospirosis and so on.

2, platelet factors and coagulation mechanism disorders: thrombocytopenic purple disease leukemia, aplastic anemia, hemophilia.

3, uremia.

4, connective tissue disease: systemic lupus erythematosus, dermatomyositis, nodular polyarteritis.

mechanism

First, lower gastrointestinal diseases

1, anal canal disease: sputum hemorrhage is due to increased intra-abdominal pressure during defecation, resulting in increased blood pressure in the iliac venous plexus, coupled with direct rubbing of hard feces caused by sputum rupture. Anal fissure can be seen in children with aphid infection causing itching of the perianal, scratching the infection and forming a severe pain with blood in the stool, with less amount and bright red. Anal thinning is most often secondary to abscess around the anorectal rectum, and a small number of secondary to intestinal tuberculosis. Near the anus, the perineal or appendix can be seen as an anal thin mouth, and pus can be seen from the thin mouth.

2, intestinal inflammatory diseases: such as acute bacterial dysentery. Acute hemorrhagic necrotic enteritis, intestinal tuberculosis, ulcerative colitis, etc., are caused by different causes of intestinal mucosa congestion, edema, erosion, ulcer bleeding and even necrosis. It is characterized by pus and blood, blood and even blood.

3, intestinal tumors: colon cancer, rectal cancer, intestinal malignant lymphoma, etc. mainly due to cancer tissue ulceration or lymphoma tissue ulceration, and the performance of bright red blood or with blood and pus blood.

Benign tumors of the small intestine, such as small intestinal neurofibroma, leiomyoma. Adenomas and other bleeding are less, but larger tumors can cause intestinal obstruction. Infection and rupture of small intestinal hemangioma can cause acute massive bleeding.

Second, lower gastrointestinal vascular disease

Mesenteric artery embolization or mesenteric arteriovenous thrombosis, intestinal torsion, intussusception, etc., due to intestinal membrane ischemia, necrosis, shedding, intestinal fistula, edema and massive serous exudation, full-thickness intestinal wall necrosis, massive bloody liquid infiltration Out, diarrhea can be seen to discharge dark red blood.

an examination

Related inspection

Ultrasound examination of gastrointestinal diseases in anal examination

First, medical history

Acute bacterial dysentery often has a history of unclean diet or contact with patients with dysentery. Patients with colon cancer, rectal cancer, and ulcerative colitis have a long history of Tibetan fluid and pus and bloody stools. They often have abdominal pain and sometimes touch the abdomen. Piece. Patients with colon polyps often have a family history. The internal hemorrhoids often bleed before and after defecation, and the blood flows out in a spray or drops blood afterwards. Patients with anal fissure often have blood in the stool during defecation and after defecation, accompanied by an anal pain that is unbearable during defecation. Patients with typhoid fever have fever, and blood in the stool appears in the second weekend and the third week. Intussusception, intestinal torsion, mesenteric artery embolism is acute, accompanied by severe abdominal distension, abdominal pain, nausea and vomiting, and severe shock may occur. Leukemia, thrombocytopenic purpura, hemophilia and other blood system diseases and blood in the stool often have a tendency to systemic bleeding.

Second, physical examination

1. Anal canal disease: The internal hemorrhoids and mixed hemorrhoids are taken out of the anus. A dark red small mass with a rounded protrusion can be seen outside the anus. The rectal examination shows that the inner iliac crest has a round dark red sputum mass. Anal fissure can be seen as a linear crack in the lower edge of the anal canal, and secondary infection can form a small ulcer. Anal thin can be seen at any time near the anus, there is a thin outer mouth in the perineum or appendix, and a little pus can be seen from the thin mouth.

2, rectal and colonic diseases: chronic non-specific rectum. Colitis examination can find tenderness in the lower abdomen and lower left abdomen, and the left lower abdomen can touch the thickened intestine of the intestinal wall. Intestinal tuberculosis, Crohn's disease, abdominal pain is often located in the right lower abdomen or umbilical cord, tenderness is obvious. Due to intestinal adhesions, the intestinal wall and mesentery are thickened, the mesenteric lymph nodes are enlarged, and the abdomen can reach the mass. Colon and rectal cancer can reach a localized mass, which is a nodular hard strip. If the cancer invades the surrounding tissue, the mass is fixed. Colon, rectum tympanic, polyp examination can be found without positive, but if the secondary infection can have local tenderness and can be combined with lower gastrointestinal bleeding.

3, small bowel disease: acute hemorrhagic necrotizing enterocolitis, often sudden onset abdominal pain, diarrhea, blood in the stool and toxemia. Abdominal pain is often located in the left upper abdomen or left middle abdomen, but also in the umbilicus or the whole abdomen, often accompanied by nausea and vomiting. The stool is dark red or bright red mushy bloody stool with a special odor. Moderate jejunum, sometimes visible peristaltic waves. Abdominal tenderness is obvious. When there is peritonitis, there may be abdominal muscle tension and rebound tenderness. When toxic intestinal paralysis occurs, the bowel sounds weaken or disappear. Intestinal typhoid hemorrhage is often in the second week of the second week of the disease course. The bloody stool is characterized by a dark red thin red bean soup. The body is found to have a typhoid face and a relatively slow pulse. Intestinal tumors cause less bleeding, small intestine malignant lymphoma, leiomyomas and other tumors, can cause partial or complete intestinal obstruction. Malignant tumors may be accompanied by bloating in addition to obstruction. Abdominal pain, loss of appetite, weight loss, abdominal mass and bloody stools. The main symptom of small intestinal hemangioma is intestinal bleeding or intestinal obstruction, which can be manifested as acute massive hemorrhage, but the most is anemia caused by long-term small blood loss.

4, lower gastrointestinal vascular disease: in addition to abdominal pain in the intussusception, the abdomen may appear in the abdomen, small intussusception mass occurs in the umbilical cord, mobility is greater, ileocecal stagnation mass is often located in the right lower abdomen, banana-shaped, The surface is smooth, the mass becomes hard when the pain occurs, and the mass becomes soft during the intermittent period. Mesenteric artery embolism often occurs on the basis of heart disease complicated with atrial fibrillation. The patient has sudden abdominal pain, which is similar to acute abdomen. Late necrosis occurs in the patient, and clinical manifestations of shock and bloody stools.

5, systemic disease: epidemic hemorrhagic fever patients with acute onset, fever, headache and low back pain, physical examination of facial flushing, low blood pressure or shock, renal damage is heavier. In addition to blood in the stool, it is often accompanied by hemoptysis, hematuria, and bleeding of the skin membrane. Patients with acute leukemia, aplastic anemia, hemophilia and other blood in the stool often have bleeding from other organs. Abnormal findings in the bone marrow examination or abnormalities in the coagulation system. Connective tissue diseases such as systemic lupus erythematosus, dermatomyositis, etc. can be found in the heart. Lung, kidney and other multiple organ damage, there may be blood in the stool when complications occur in the gastrointestinal tract.

Third, laboratory inspection

1, stool examination: bacterial dysentery, ulcerative colitis and amoebic bowel disease, routine examination can be pus and bloody stools, but ulcerative colitis feces repeatedly cultured without pathogenic bacteria, and bacterial dysentery can be cultivated Pathogenic bacteria. Patients with amebic bowel disease, repeated microscopic examination of fresh feces can be found in the melilatory tissue amoeba trophozoites or cysts.

2, blood test: blood culture in typhoid patients can find pathogenic bacteria, leukemia patients can detect naive cells in the blood, bone marrow examination can confirm the diagnosis. Abnormal platelet counts can be found in peripheral blood and bone marrow examinations of thrombocytopenia.

Fourth, equipment inspection

1, X-ray barium meal and barium enema examination: X-ray barium meal, especially gas sputum double contrast can improve the X-ray diagnosis rate. If necessary, combined with small bowel angiography and barium enema examination have certain diagnostic value for small intestine polyps, diverticulum, intestinal tuberculosis, Crohn's disease, colonic tumor and ulcerative colitis.

2, endoscopy: fiber colonoscopy can be found in the rectum, sigmoid colon and the entire colon lesions, especially the wide application of electronic colonoscopy for the diagnosis and treatment of colorectal lesions. During the operation, the video can be recorded, and the lesion can be diagnosed and treated by brushing, biopsy, electric cutting, and hemostasis. In recent years, enteroscopy has begun to be used in clinical practice, and has a certain diagnostic value for unexplained small intestinal bleeding. However, due to the difficulty of operation, it has not been widely used.

3, selective celiac angiography: after the above examination of the bleeding site and the cause of bleeding is still unclear, selective celiac angiography can be performed. Generally, when the bleeding rate is 0.5 mL or more per minute, the angiography can show the bleeding site.

Differential diagnosis

Since there are many diseases that cause blood in the stool, the following is a brief identification of only common diseases.

1. nucleus or anal fissure, anal fistula

(1) is one of the common causes of blood in the stool, especially the bleeding of internal hemorrhoids is very common.

(2) The color of the blood is generally bright red, and it is not mixed with the feces, and does not contain mucus. In most cases, it is characterized by dripping blood after the stool, especially when the stool is indurated.

(3) Patients with anal fissure often have pain when defecation.

(4) Anal examination and finger examination can often be diagnosed.

(5) Anoscope or proctoscopy is conducive to diagnosis, and can directly peep into the hemorrhoids such as the nucleus.

2. Bacterial dysentery

(1) In the acute phase, there are often symptoms such as chills, fever, and pain in the lower abdomen. The stool is often a pus-like blood sample, each time the amount is not much, often accompanied by a sense of urgency and urgency; the chronic phase is an intermittent episode of mucus, pus and blood.

(2) A large number of pus cells, red blood cells and macrophages can be found in routine stool examinations; pathogenic bacteria (Shigella dysenteriae) can be found in stool culture, but the positive rate of chronic period stool culture is not high, only 15% to 30%.

(3) Colonoscopy showed diffuse hyperemia and edema in the mucosa of the lesion. The ulcer was more superficial and the edges were often irregular.

3. Amoebic dysentery

(1) The stool is mostly jam-like, or dark red, with a large amount, often accompanied by purulent mucus. The patient has fever, abdominal distension, abdominal pain and severe performance after urgency.

(2) routine examination of stool can be found in piles of red blood cells and a small number of white blood cells, such as the discovery of lytic tissue amoeba trophozoites or cysts have a diagnostic value.

(3) Colonoscopy can be seen mucosal congestion, but the edema is not significant, the ulcer is generally deep, often a small bottle-like ulcer with a small mouth and a normal mucosa between the ulcers. The lesion can occur anywhere in the large intestine.

4. Schistosomiasis

(1) There is a history of contact with infected water, often manifested as chronic diarrhea, stool is pus-like blood or blood for stool.

(2) Other clinical manifestations of schistosomiasis, such as hepatosplenomegaly and decreased whole blood cells.

(3) B-mode ultrasound can detect liver fibrosis.

(4) colonoscopy can be seen in the rectal mucosa with miliary yellow nodules, sometimes ulcers or polyps can be seen, rectal mucosal biopsy can be found schistosomiasis eggs.

5. Ulcerative colitis

(1) It is a non-specific colonic inflammation with unknown etiology. The lesions are recurrent and relieved, and they are delayed. There are abdominal pains and diarrhea in the attack period, often accompanied by urgency and weight. This disease is often the first to invade the rectum and sigmoid colon, and then the lesion can gradually spread upwards and reach the ileocecal area; a small number of patients can start from the right colon and then gradually spread to the left colon. The stool is usually a mucus pus and a bloody stool.

(2) RBC and white blood cells can be seen in routine stool examination, but the feces are repeatedly cultured without pathogen growth.

(3) During the active period of the lesion, colonoscopy showed diffuse hyperemia, edema, superficial small ulcer, increased fragility of the mucous membrane, and easy bleeding; mucosal biopsy, pathological findings such as reduction of glandular goblet cells and discovery of crypt abscess It is helpful for diagnosis. Inflammatory polyps can sometimes be found in the intestines of the chronic phase, and the intestinal wall of the elderly is thickened.

(4) X-ray barium enema can also help the diagnosis, showing the disappearance of mucosal folds and disappearance of the colonic bag.

(5) The antibacterial treatment effect is poor, and the treatment with sulfasalazine or 5-aminosalicylic acid and adrenal glucocorticoid can effectively alleviate the disease.

6. Intussusception

(1) Excretion of mucus and blood, often without stool. Sometimes the abdomen can reach the nested mass.

(2) X-ray barium enema examination can not only confirm the diagnosis, but also achieve the purpose of treatment.

7. Rectal cancer

(1) is one of the common cancers. Patients over the age of 35, suffering from chronic diarrhea or recurrent mucus pus and bloody stools, accompanied by urgency and heavy weight, should be considered for rectal cancer when the general anti-inflammatory treatment is not effective.

(2) The rectal examination can find the lesion, which is very helpful for diagnosis. Rectal cancer is characterized by irregular, hard masses on the intestinal wall, with tenderness, and the surface of the mass is often uneven; the fingertips often have mucus and pus. The vast majority of rectal cancer can be found by fingerprints.

(3) colonoscopy can directly observe the shape and extent of the cancer, combined with biopsy can confirm the histological diagnosis.

8. Colon cancer

(1) Patients with middle-aged or older have changes in bowel habits, diarrhea or constipation, thin stools, suspected mucus and pus and suspected colon cancer, and a small number of patients may only present with fixed abdominal pain.

(2) Right colon cancer is mainly characterized by abdominal pain and diarrhea. Pus routine cells can be found in pus cells, red blood cells, or occult blood test. Left colon cancer is often characterized by thin stools or constipation, and stool. It can also be accompanied by mucus or pus. A small number of patients develop symptoms of intestinal obstruction.

(3) Some cases may have a fixed mass in the abdomen and tenderness.

(4) Late cases have symptoms such as weight loss and anemia.

(5) colonoscopy can be found in the location, size and extent of the cancer, combined with biopsy to confirm the diagnosis.

(6) X-ray barium enema is also helpful for diagnosis, especially for the diagnosis of intestinal stenosis due to cancer infiltration, which is superior to colonoscopy.

9. Rectal and colon polyps

(1) is one of the common causes of blood in the stool, especially children and adolescents.

(2) When the rectum, sigmoid colon or descending colon polyps, it is characterized by fresh blood attached to the stool, and the blood and feces are not mixed. If it is a right colonic polyp, the blood can be mixed with the stool, but when the amount of bleeding is large, the blood can be dark red, and when the amount of bleeding is small, it can be black.

(3) A small number of patients have a family history.

(4) X-ray barium enema examination can be seen in the round or oval filling defect, which is helpful for diagnosis.

(5) Colonoscopy can detect the location, shape and quantity of polyps, and biopsy can be performed to determine the pathological type of polyps.

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