What causes blood in the stool?

In fact, when going to the toilet, anal pain and dry stools often occur. In severe cases, blood in the stool may appear. Some blood in the stool is in the form of water drops, some is in the form of penetration, and some is in the form of jetting. In addition to being related to hemorrhoids, it is also possible that it is related to the digestive system. Blood in the stool includes systemic diseases and systemic infectious diseases. The specific cause of blood in the stool can be determined based on the individual's age, pathological factors, and recent physical characteristics.

Depending on the location of bleeding, it can be divided into upper gastrointestinal bleeding and lower gastrointestinal bleeding.

Because the bleeding location of upper gastrointestinal bleeding is relatively high, after the red blood cells pass through the digestive tract, the stool will appear black, which we call tarry stool. If the amount of bleeding is small, it may not be easily noticed. Large amounts of upper gastrointestinal bleeding and the appearance of black stools often indicate bleeding in the esophagus, stomach and duodenum. Common causes include esophageal varicose bleeding, gastroduodenal ulcer bleeding, etc.

Because lower gastrointestinal bleeding is located relatively low, the bloody stools are mostly bright red or dark red. The more common ones include anal fissure, hemorrhoids, polyps, Michael diverticulum, tumors, etc. Children with prolonged diarrhea and damaged perianal skin and mucous membranes may also have bloody stools.

In addition, some systemic diseases: such as coagulation dysfunction, acute infectious diseases (hemorrhagic fever, typhoid fever, paratyphoid fever), parasitic diseases (hookworm disease, schistosomiasis), sepsis, food and drug poisoning, hereditary hemorrhagic telangiectasia, etc. can cause bloody stools.

The above are common causes. Bleeding from different causes has certain characteristics, and a preliminary judgment can be made based on these characteristics before a detailed examination.

1. Age:

① Newborns: focus on excluding swallowing of blood from other parts of the body, spontaneous hemorrhage, hemorrhagic necrotizing enteritis, and digestive tract malformations;

②Infants and young children: focus on excluding intussusception, intestinal polyps, anal fissures, and Michael’s diverticulum;

③ During school age, pay attention to gastric and duodenal ulcers, esophageal bleeding, allergic purpura, etc.

2. Color and bleeding amount:

① A small amount of blood in the stool, bright red, and fresh blood attached to the surface of the stool is mostly bleeding from rectal, sigmoid colon or descending colon diseases;

② Large amounts of blood in the stool, dark red or black, are mostly caused by bleeding from the upper gastrointestinal tract or acute hemorrhagic necrotizing enteritis, typhoid fever, etc.

③Jam-like stool is a mixture of blood and mucus like sticky jelly stool. If the child is between 6 and 18 months old and accompanied by paroxysmal crying and noise, intussusception should be considered.

④ If the child does not cry or make noise when defecating, rectal polyps should be considered. If the child cries and makes noise a lot, anal fissure should be considered, which is also seen in intussusception.

⑤Infants under 6 months old have no obvious blood in the stool, only a positive occult blood test, accompanied by eczema and eosinophilia, indicating a high possibility of milk protein allergy.

⑥ Bloody stool: If there is no pain, pay attention to eliminate polyps. If there is abdominal pain, pay attention to dysentery, parasitic diseases, etc.

3. Relationship with defecation:

① Blood drips after defecation and is not mixed with stool. It is often seen in hemorrhoids and anal fissures;

②Accompanied by severe abdominal pain: intussusception, hemorrhagic necrotizing enteritis;

③Pain during defecation: anal fissure.

In summary: when bloody stools occur, first determine whether it is bleeding, then determine the bleeding site and amount, and finally rely on a careful physical examination and auxiliary examinations to make a clear diagnosis. If parents encounter bloody stools, they should send the stool for examination immediately and ask the doctor for details. Do not delay the treatment of the disease!