INTRODUCTION — Seeing blood on your child's stool can be frightening. However, this is a common condition in children and is usually not serious. There are many possible causes of bloody stools, also known as "rectal bleeding." The most likely cause depends on the frequency and amount of blood, and on your child's age and underlying condition. A health care provider can help to determine the source of the bleeding and the most appropriate treatment.

This article will review some of the common causes of bloody stools and tests that may be used to evaluate your child. Bloody stools in adults is discussed separately. (See "Patient education: Blood in the stool (rectal bleeding) in adults (Beyond the Basics)".)

WHEN TO SEEK HELP — Most children with minor rectal bleeding do not have a serious condition. However, it is not possible to know the cause of rectal bleeding without an examination. Thus, if you notice that your child has rectal bleeding, you should talk to your child's health care provider to determine if an examination is needed. (See 'Rectal bleeding tests' below.)

TYPES OF RECTAL BLEEDING — Bloody stools usually indicate bleeding in the upper digestive tract (stomach and small intestine) and/or the lower digestive tract (the colon, rectum, and anus) (figure 1).

●Bleeding from the upper digestive tract usually causes black, tarry stools. In many cases, the child also vomits red or black material that looks like coffee grounds.

●Bleeding from the lower digestive tract usually causes the stool to be coated or mixed with bright red blood or occasionally to appear maroon colored.

●Certain foods and medications can also cause the stool to appear bloody. A list of these foods and medications is provided in table 1 (table 1).

However, it is not always possible to know the source or type of rectal bleeding based upon the appearance of the stool alone. Bloody stools can even come from other places, including bleeding from the nose and throat. An evaluation and physical examination is necessary in most cases. (See "Lower gastrointestinal bleeding in children: Causes and diagnostic approach".)

RECTAL BLEEDING CAUSES

Anal fissure — An anal fissure is a cut or tear in the lining of the anus (the opening through which stool passes out of the body) that can develop when an infant or child passes a large or hard stool. Anal fissures can occur in all age groups, from newborns to school-aged children and even adults (see "Patient education: Anal fissure (Beyond the Basics)"). The symptoms of an anal fissure include pain, straining, or grunting during a bowel movement and bright red blood on the outside of the stool or with wiping.

Many infants and children with anal fissures also have a history of constipation or fairly hard stools. Treatment of constipation is discussed separately. (See "Patient education: Constipation in infants and children (Beyond the Basics)".)

Milk or soy protein intolerance — Milk or soy protein intolerance (also known as "allergic" colitis, milk or soy protein-induced colitis, or protein-induced proctitis or proctocolitis) is a condition that can develop in infants. It is caused by a sensitivity to the protein in cow's milk or soy and usually develops after starting formula. It can also occur in breastfed infants as a result of cow's milk or soy products consumed by the mother. The protein intolerance frequently resolves by one year of age.

In addition to blood-tinged or bloody stools, symptoms of milk or soy protein intolerance sometimes include vomiting, diarrhea, irritability, poor weight gain, and eczema. Children with these symptoms should be evaluated by a medical provider. If the health care provider concludes that milk or soy protein intolerance is the most likely cause, the next step is a diet that does not contain milk or soy protein. This diet is described in a separate article. (See "Food protein-induced allergic proctocolitis of infancy", section on 'Management' and "Patient education: Acid reflux (gastroesophageal reflux) in infants (Beyond the Basics)", section on 'Milk-free diet'.)

Less common causes

●Inflammatory bowel disease is a chronic inflammatory condition in which the lining of the digestive tract becomes inflamed. There are two types: Crohn disease and ulcerative colitis. The inflammation leads to symptoms, such as bloody stools, diarrhea, lack of appetite, and weight loss. Crohn disease and ulcerative colitis are discussed in more detail in separate articles. (See "Clinical manifestations and complications of inflammatory bowel disease in children and adolescents" and "Clinical presentation and diagnosis of inflammatory bowel disease in children".)

●Infectious diarrhea is diarrhea caused by a virus, bacterium, or parasite that can cause bloody stools in preschool- and school-aged children, as well as in adolescents. Infectious diarrhea can develop as a result of eating or drinking contaminated foods/drinks/water or, less commonly, after taking a course of antibiotics. (See "Patient education: Foodborne illness (food poisoning) (Beyond the Basics)" and "Patient education: Antibiotic-associated diarrhea caused by Clostridioides difficile (Beyond the Basics)".)

Symptoms of infectious diarrhea usually include bloody diarrhea, fever, and abdominal pain. Treatment of diarrhea in children is discussed separately. (See "Patient education: Acute diarrhea in children (Beyond the Basics)".)

●Juvenile polyps are growths of tissue projecting from the inner lining of the colon that can develop in children, typically between the ages of two and ten years. Symptoms usually include painless rectal bleeding. Single juvenile polyps are not usually cancerous or precancerous but should be evaluated by a health care provider and usually require removal. (See "Lower gastrointestinal bleeding in children: Causes and diagnostic approach", section on 'Juvenile polyps'.)

Rarely, multiple or large polyps are present in the colon in children or adolescents and cause rectal bleeding. Some of the conditions associated with this presentation in children and teenagers are: solitary juvenile polyps, juvenile polyposis syndrome, Peutz-Jeghers syndrome, familial adenomatous polyposis, and hereditary nonpolyposis colon cancer syndrome (formerly known as Lynch syndrome). These conditions are often inherited, and patients may have family members who are affected (see "Patient education: Familial adenomatous polyposis (The Basics)" and "Peutz-Jeghers syndrome: Clinical manifestations, diagnosis, and management"). In addition, tumors may present with rectal bleeding, but tumors are a very rare cause of rectal bleeding in children and adolescents. The tumors may be primary, meaning they originate in the gastrointestinal tract, or may be metastatic, which means they may originate elsewhere in the body.

●Meckel's diverticulum is a congenital (present at birth) outpouching in the lower part of the small intestine and is left over from the umbilical cord. It may contain cells normally found in the stomach that can secrete acid and cause ulcers and bleeding in the small bowel near the diverticulum, which results in bleeding from the rectum. The bleeding can occur at any age, but approximately one-half of the cases are in children. Occasionally, a Meckel's diverticulum can cause a very large amount of bleeding, which can be dangerous and requires immediate medical attention. (See "Patient education: Meckel's diverticulum (The Basics)".)

●A number of other more serious conditions can cause rectal bleeding because of obstruction (blockage) of the bowels. These include intussusception (a form of bowel obstruction in which a part of the intestine "telescopes" into an adjacent part of the intestine) or Hirschsprung disease (a form of colon obstruction that develops before birth and caused by the absence of nerve cells in the large bowel). Most of these conditions cause the infant or child to become ill suddenly. If your child suddenly develops bloody stools and becomes lethargic, has abdominal pain, fever, vomiting, a distended abdomen, or other unusual symptoms, call your child's health care provider immediately. (See "Intussusception in children" and "Congenital aganglionic megacolon (Hirschsprung disease)".)

●Other conditions that can cause rectal bleeding include a blood clotting disorder or abnormalities of the blood vessels inside the bowel, which can cause excessive bleeding. These causes may be accompanied by changes in the skin (easy bruising, certain rashes, or other findings) or other symptoms that can help the doctor or nurse choose tests to diagnose the problem.

RECTAL BLEEDING TESTS — Sometimes a health care provider can determine the cause of the bleeding by inspecting the outside of the anus. This may include a brief examination of the inside of the anus using a finger (rectal examination). The health care provider can also test a sample of stool to be sure whether or not it contains blood. The stool can be tested for infection by a bacterium, virus, or parasite by sending a specimen to the laboratory for testing.

This examination may be all that is necessary. If the cause of the bleeding is not clear based upon the examination, further testing may be recommended. This might include blood tests and, in some cases, a colonoscopy (figure 2) and/or upper endoscopy (figure 3). Colonoscopy is an examination of the lower part of the gastrointestinal tract (also known as the colon or large bowel), which is performed by insertion of a thin, flexible tube with a camera attached. An upper endoscopy is a similar procedure in which the health care provider examines the upper part of the gastrointestinal tract, which includes the esophagus, the stomach, and the duodenum (the first section of the small intestine). (See "Patient education: Colonoscopy (Beyond the Basics)" and "Patient education: Upper endoscopy (Beyond the Basics)".)

Other tests may also be helpful in some cases. If examination of the small bowel is needed to identify the source of bleeding, tests may include may include video capsule endoscopy, upper gastrointestinal series with small bowel follow-through (UGI/SBFT), or magnetic resonance enterography. Other tests may include computed tomography (CT), ultrasound, nuclear medicine studies (Meckel scan or tagged red blood cell scan), or angiography. The health care provider chooses between these tests depending on the child's history and symptoms.

RECTAL BLEEDING TREATMENT — As discussed above, there are a number of potential causes of bloody stools. Your child's health care provider will determine if the underlying condition requires treatment. Even if your child's bleeding seems minor or resolves on its own, your child should be evaluated by a health care provider.

WHERE TO GET MORE INFORMATION — Your child's health care provider is the best source of information for questions and concerns related to your child's medical problem.

This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Bloody stools (The Basics)

Patient education: GI bleed (The Basics)
Patient education: Angiodysplasia of the GI tract (The Basics)
Patient education: Meckel's diverticulum (The Basics)
Patient education: Ulcerative colitis in children (The Basics)
Patient education: Crohn disease in children (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Blood in the stool (rectal bleeding) in adults (Beyond the Basics)
Patient education: Anal fissure (Beyond the Basics)
Patient education: Constipation in infants and children (Beyond the Basics)
Patient education: Acid reflux (gastroesophageal reflux) in infants (Beyond the Basics)
Patient education: Foodborne illness (food poisoning) (Beyond the Basics)
Patient education: Antibiotic-associated diarrhea caused by Clostridioides difficile (Beyond the Basics)
Patient education: Acute diarrhea in children (Beyond the Basics)
Patient education: Crohn disease (Beyond the Basics)
Patient education: Ulcerative colitis (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Lower gastrointestinal bleeding in children: Causes and diagnostic approach
Approach to upper gastrointestinal bleeding in children
Food protein-induced allergic proctocolitis of infancy
Clinical presentation and diagnosis of inflammatory bowel disease in children
Clinical manifestations and complications of inflammatory bowel disease in children and adolescents
Intussusception in children
Meckel's diverticulum

The following organizations also provide reliable health information.

●National Library of Medicine

(www.nlm.nih.gov/medlineplus/ency/article/003130.htm)

●GI Kids (from the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition)

(www.gikids.org/content/41/en/bleeding/lower)

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ACKNOWLEDGMENT — The editorial staff at UpToDate would like to acknowledge George D Ferry, MD, who contributed to an earlier version of this topic review.