What is the most accurate test for blood in the stool

The state of stool can reveal a person's gastrointestinal condition, so if people find that there is something wrong with their stool, they will go directly to the hospital for examination. If there is blood in the stool, what test is the most accurate? Usually, the most likely cause of blood in the stool is hemorrhoids. In addition to this reason, there may also be rectal diseases, etc., so abdominal ultrasound examination, fiber endoscopy examination, etc. are needed at this time. Let's learn about the details together.

Generally speaking, heavy blood in the stool indicates bleeding in the lower gastrointestinal tract (especially the colon and rectum). Blood in the stool accompanied by hematemesis indicates upper gastrointestinal bleeding. Upper gastrointestinal bleeding mostly discharges dark red blood or black stools that are tarry, while lower gastrointestinal bleeding mostly discharges bright red or bright red blood.

(1) Lower gastrointestinal diseases:

① Anal canal diseases, such as hemorrhoids, anal fissures, and anal fistulas.

② Rectal diseases, such as ulcerative colitis, tuberculous rectal ulcers, anal canal injury, rectal injury, rectal carcinoid, etc.

③Colon diseases, such as acute bacillary dysentery, chronic nonspecific ulcerative colitis (chronic colitis), colon cancer, etc.

④Small intestinal diseases, such as acute hemorrhagic necrotizing enteritis, Crohn's disease, small intestinal tumors, etc.

(2) Upper gastrointestinal diseases: such as gastric and duodenal ulcers, cancer, etc.

(3) Intra-abdominal vascular diseases: such as ischemic colitis. Acute portal vein thrombosis, etc.

(4) Systemic and toxic diseases: such as blood diseases, acute infectious and parasitic diseases, hemorrhagic fever, vitamin K deficiency, poisoning or drug toxicity, etc.

The main tests for blood in the stool are as follows:

① Fiberoptic endoscopy: If the patient has tarry stools, a fiberoptic gastroscopy is required; if there is fresh blood in the stool, a colonoscopy is required.

② Abdominal B-type ultrasound examination: It can determine whether there is a mass in the abdomen and its location and size, and may also observe whether there are abnormal lymph nodes in the abdomen, thereby clarifying the cause of bloody stools.

③Selective arteriography: It has diagnostic significance for blood in the stool caused by vascular reasons.

④ Routine stool examination: If there are more red blood cells and white blood cells in the stool, it indicates that the blood in the stool may be caused by bacterial dysentery; if amoeba is found in the stool microscopy, it indicates that the blood in the stool is caused by amoebic dysentery; if schistosome eggs are found in the stool microscopy, it indicates that the blood in the stool is caused by schistosomiasis.

⑤ Stool culture: If the pathogenic bacteria that cause bloody stools are cultured, it will help to differentiate between bacterial dysentery, typhoid fever and paratyphoid fever.

⑥ Platelet examination: If the platelet count is low, it indicates that the blood in the stool is caused by thrombocytopenia due to various reasons.

⑦ Determination of bleeding time and coagulation time: If both are prolonged, it indicates that blood in the stool is caused by coagulation dysfunction.