In the outpatient clinic, I often encounter many patients with blood in the stool. The first question asked is "Doctor, do I have bowel cancer?". The following summarizes some common questions about blood in the stool that patients most want to know. Helped.
The blood is discharged from the anus, and the color of stool is bright red, dark red or tarry (black stool). If it is a small amount of bleeding, the color of stool will not change, and it can be confirmed by occult blood testing. All are called blood in the stool. First, we should rule out black stools caused by eating too much meat, animal liver, animal blood, or drugs (bismuth, carbon powder, or traditional Chinese medicine).
1. Causes of blood in the stool:
1. It is common in gastrointestinal bleeding. Bleeding may occur anywhere from the mouth to the anus. Examples: rupture and bleeding from esophageal/gastric varices, gastric and intestinal ulcers and inflammations, infectious diseases, tumors (polyps and cancer of the stomach and colorectal), hemorrhoids, anal fissures, dry stools, etc. Adult blood in the stool is mostly caused by hemorrhoids, anal fistulas, anal fissures, intestinal polyps, intestinal cancer, and inflammatory bowel disease. Children's blood in the stool is mostly caused by intestinal polyps. The blood is bright red, painless, and the blood does not mix with stool; it can also be seen in bacillary dysentery, intussusception, and blood system diseases.
2. It is also rare in blood system diseases and other systemic diseases, such as leukemia, diffuse intravascular coagulation, etc.
2. Clinical manifestations 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 gastrointestinal tract.
1. Bloody stools: mostly acute bleeding. The color is bright red or purple, dark red, and it can coagulate into blood clots after a while. Common diseases:
(1) Hemorrhoids: Both external hemorrhoids and mixed hemorrhoids can cause fecal bleeding in various periods, usually with blood in the stool or dripping blood after the stool. External hemorrhoids generally have no stool bleeding.
(2) Anal fissure; the bleeding method is that there is blood on the side of the stool, which does not mix with the stool, and some patients drip blood after the stool.
(3) Colorectal polyps; painless stool bleeding. Bleeding during defecation, and stop after defecation, the amount varies. Generally, blood does not mix with feces, or polyps are high in position and large in number, and can also mix with feces.
(4) Pus blood/mucus blood in the stool; that is, there are both pus (mucus) fluid and blood in the excreted stool. Pus (mucus) and bloody stools are often found in tumors and inflammations in the rectum or colon. The following diseases are common:
(5) Colorectal cancer; blood in the stool in the early stage of colorectal cancer is often mistaken for hemorrhoids in the stool, and it is not taken seriously. Blood in the stool caused by hemorrhoids and anal fissures is bright red, with blood (toilet paper stained with blood, blood attached to the periphery of the stool), dripping (blood dripping down), or blood ejection. Colorectal tumors also have blood in the stool, but the common blood color is dark red, purplish red or accompanied by mucus. Blood, mucus, and feces are often mixed, and there are rarely symptoms of dripping or ejection. If blood in the stool is found, pay attention to observe the blood in the stool and seek medical treatment in time.
(6) Ulcerative colitis; mucus or pus and blood in the stool, accompanied by pain in the left lower abdomen or lower abdomen.
(7) Intestinal infectious diseases; such as bacillary dysentery, amoebic enteropathy, etc.
2. Black stool; also known as tarry stool, the stool is black or brown-black. It is one of the most common symptoms of upper gastrointestinal bleeding. If the amount of bleeding is small and the bleeding rate is slow, the blood stays in the intestine for a long time, and the excreted stool is black; if the amount of bleeding is large and the residence time in the intestine is short, the discharged blood is dark red; The amount of bleeding is particularly large, and it can be bright red when it is discharged quickly.
3. Occult blood in the stool; a small amount (minor amount) of gastrointestinal bleeding will not cause the color of the stool to change, and it is only positive in the stool occult blood test, which is called occult blood in the stool. All diseases that cause gastrointestinal bleeding can cause occult blood in the stool, common ulcers, inflammations and tumors. The fecal occult blood test can detect small (trace) blood components in the stool. The early fecal occult blood of intestinal polyps (cancer) can be positive, and regular fecal occult blood testing is an important way for colorectal tumor screening (primary screening).
Accompanying symptoms Due to different causes, the accompanying symptoms and signs are also different. Detailed medical history should be asked, and physical examination should be perfected to guide the next diagnosis and treatment plan.
1. Abdominal pain; clinically, the disease can be preliminarily judged based on the nature of abdominal pain. Upper abdominal cramps with jaundice often indicate biliary bleeding; if chronic abdominal pain is obviously periodic, seasonal and rhythmic, peptic ulcers should be considered; bloody stools or pus during abdominal pain, and abdominal pain-defecation-abdominal pain relief regularity It is found in bacillary dysentery and ulcerative colitis; in addition, abdominal pain can also occur in colorectal cancer, intussusception, mesenteric thrombosis, and ischemic bowel disease.
2. Tenesmus and heavy; that is, distress during defecation, anal swelling, and a sense of unclean defecation, which often indicates rectal and perianal diseases, such as proctitis, rectal cancer, hemorrhoids, etc.
3. Systemic bleeding tendency; blood in the stool with bleeding in the skin and mucous membranes is seen in acute infectious diseases and blood diseases, such as epidemic hemorrhagic fever, allergic purpura and hemophilia.
4. Skin changes; patients with spider veins and liver palms need to be alert to the possibility of portal hypertension in liver cirrhosis; if the skin and mucous membranes have telangiectasias, hereditary telangiectasias should be excluded.
5. Abdominal lumps: Crohn’s disease, intussusception, tuberculosis and malignant tumors of the abdominal cavity should be considered for patients with blood in the stool and abdominal lumps.
1. Laboratory examination: including blood, urine, and stool routine; stool without gross blood but occult blood can be checked for fecal occult blood test. It can carry out fecal bacterial culture, parasite detection; biochemical examination and tumor markers, etc.
2. Etiological examination: (1) Imaging examination of abdominal ultrasound, CT, MRI, gastro/colonoscope, enteroscopy, capsule endoscopy, duodenoscope, etc. to determine the location and nature of the digestive tract disease.
(2) Bone marrow puncture examination, except for blood system diseases.
(3) Digital anus examination helps to find rectal tumors (very important examination).
1. Pay attention to the characteristics of blood in the stool:
(1) Distinguish the characteristics of blood in the stool, bleeding pattern, color and bleeding volume. Such as internal hemorrhoids bleeding in the form of drips or jets; anal fissures are more obvious pain in the stool, blood attached to the surface of the stool or stained with blood on the toilet paper, and the amount of bleeding is small; chronic non-specific colitis, colon polyps, etc. often show repeated and intermittent small amounts of blood in the stool ; If there is a lot of bleeding, the blood is stored in the intestinal cavity, and it may appear black when discharged. Consider upper gastrointestinal lesions; if it is purple, dark red or blood clots; or blood is bright red, it mostly comes from the lower gastrointestinal tract; mixed There is mucus and foul smell, and changes in bowel behavior and regularity. It should be thought of the possibility of colorectal malignancy.
2. Pay attention to the accompanying symptoms of blood in the stool
(1) Blood in stools such as proctitis and rectal polyps (cancer) are often accompanied by anal fall, tenesmus; internal hemorrhoids and polyps have blood in the stool without anal pain; anal fissures are accompanied by anal pain and constipation; chronic colitis is often accompanied by diarrhea and left lower abdominal pain ; Hemorrhagic necrotizing colitis, intussusception accompanied by severe abdominal pain and even shock.
Five, differential diagnosis
It is mainly differentiated from the primary disease of hematochezia, based on the characteristics of hematochezia and accompanying symptoms, laboratory examinations, and imaging examinations. In addition, blood products, drugs, etc. may also change the color of feces, which should be noted and identified.
Mainly for the treatment of the primary disease.