Author: Alicia Cole, Krizun Loganathan, Sharryn Gardner / Editor: Lauren Fraser / Codes: GC7, GP8, HP3, SLO2, SLO5, SuC11, SuC13, SuC7, SuP5Published: 04/11/2021


According to a 2014 study1, rectal bleeding accounts for 0.3% of presentations to the emergency department.

The University Hospital of Wales performed a retrospective case note review2 of children presenting to the emergency department over 2 years and found lower gastrointestinal bleeding (LGIB) made up 0.14% of all presentations to paediatric ED, with a median age at presentation of 5 years and an even spread between sexes. Of those presenting with LGIB, 24% required admission and only 5% required urgent intervention. The authors concluded that a ‘high index of suspicion remains necessary to identify infrequent but serious pathology’.


Lower gastrointestinal bleeding is bleeding from the rectum which starts distal to the ligament of treitz, a fold of peritoneum which holds up the duodenojejunal flexure.3

It comprises:

  • Haematochezia: bright red blood passed rectally
  • Malaena: black, tarry stool, suggesting altered blood which has been partially digested after a prolonged period passing through the GI tract.

Embryologically the beginnings of the GI tract are formed at the 4th week of gestation. Due to the rapid growth of the intestinal loop, it becomes too large to remain in the abdominal cavity, and therefore expands into the yolk sac (future umbilicus). The loop returns to the abdomen by the 8th week of gestation. As it re-enters the abdomen it rotates, and is fixed into position.4

Learning bite

If this part of foetal development goes wrong, it can result in malrotation, which will be discussed later.

Once development is complete, 3 distinct lengths of the GI tract can be separated according to their blood supply:

  • Foregut: coeliac axis
  • Midgut: superior mesenteric artery
  • Hindgut: inferior mesenteric artery

Another relevant embryological structure is the vitelline duct, which connects the yolk sac to the mid-end ileum within the foetus. If this structure persists into infancy it is named Meckel’s diverticulum. Due to its rich arterial supply from the vitelline artery (a branch of the superior mesenteric artery) it can cause bleeding in the GI tract.5

Causes of lower GI bleed in children

The cause of LGIB in children tends to depend on age as displayed in the table below. See the left column for conditions more unique to their age group, and the right column for conditions which can overlap.

Neonate Swallowed maternal blood Necrotising enterocolitis Hirschsprung’s disease with enterocolitis Malrotation with midgut volvulus Coagulopathy Vascular malformations Brisk upper GI bleeding GI duplication cyst Allergic colitis Anal fissure
Infancy (1 month-2 years) Meckel’s diverticulum Intussusception Infantile/very early onset inflammatory bowel disease (VEO-IBD) Infectious colitis Foreign body Malrotation Vascular malformation Hirschsprung’s disease enterocolitis Anal fissure Allergic colitis
Preschool (2-5 years) Juvenile polyps Immunoglobulin A vasculitis (Henoch-Schonlein Purpura/HSP) Haemolytic-Uraemic-Syndrome (HUS) Solitary rectal ulcer syndrome Anal fissure Infectious colitis Vascular malformation VEO-IBD Intussusception Meckel’s Diverticulum Foreign body
School age (5-16 years) Inflammatory bowel disease Haemorrhoids Anal fissure Infectious colitis HSP HUS Meckel’s diverticulum Juvenile polyps Foreign body


Key clinical features of diagnoses

Swallowed maternal blood

  • Occurs secondary to cracked/sore nipples in breast fed babies

Necrotising enterocolitis (NEC)

  • Bowel ischaemia and necrosis causing LGIB
  • Aetiology poorly understood but more common in preterm/low birth weight babies
  • Can present with various symptoms – poor feeding, bilious vomiting, abdominal distension

Hirschsprung’s disease with enterocolitis

  • Hirschsprung’s disease is a congenital malformation resulting in aganglionic portions of bowel which are unable to undergo peristalsis
  • Hirschsprung associated enterocolitis is a form of toxic megacolon, which is a medical emergency, and can present with lower GI bleeding

Malrotation with midgut volvulus

  • During gestation the midgut rotates within the abdominal cavity, in malrotation this does not occur in the normal way, giving rise to the potential for the midgut to form a volvulus.
  • The volvulus can cause an obstruction which can lead to bowel ischaemia and therefore bleeding


  • These include:
    • Vitamin K deficiency
    • Von Willebrand disease
    • Haemophilia

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There are multiple causes of coagulopathy which typically present with other symptoms in the neonate (cephalhaematoma at birth, oozing from the umbilicus), but can also cause lower GI bleeding.

Anal fissures

  • Can occur at any age, starting in the neonatal period
  • Associated with difficult defaecation or straining
  • Commonly suggests underlying constipation

Allergic colitis

  • Occurs in 5-15% babies
  • Can be triggered by a cow’s milk protein, or soy protein allergy which results in an inflammatory colitis which can present with diarrhoea, faltering growth and LGIB
  • Occurs in bottle fed and breast-fed babies, due to dairy or soy milk which can be found in the breast-feeding adult’s diet
  • Frequently resolves around 18 months of age and dairy/soy can be gradually reintroduced into the baby’s diet

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When reintroducing dairy into a child’s diet, the ‘milk ladder’ can be used, gradually increasing the amount of dairy a child is exposed to.

GI duplication cysts

  • Congenital malformations commonly found in the jejunum and ileum
  • Case study reports suggest they can contain ectopic GI mucosa which can cause LGIB
  • More frequently present with obstruction, can be a lead point for intussusception

Vascular Malformations

  • Congenital telangiectasias can occur in children with certain congenital diseases e.g.
    • Hereditary Haemorrhagic Telangiectasia (Osler-Weber-Rendu)
    • Klippel-Trenaunay Syndrome
    • Turner’s Syndrome
  • These can all produce GI telangiectasias which can produce significant lower GI bleeding

Meckel’s Diverticulum

  • See ‘pathophysiology’ for embryological origin of Meckel’s diverticulum
  • Bleeding can result from acid production by ectopic mucosa found within the diverticulum
  • The severity and chronicity of the bleeding can vary
  • 60% of patients who present with LGIB secondary to Meckel’s diverticulum are younger than 2 years old


  • This occurs when a portion of bowel ‘telescopes’ within itself
  • In children under 2 it is commonly idiopathic but in older children the lead point is more commonly a duplication cyst or a Meckel’s diverticulum
  • Presents with paroxysmal abdominal pain which can transiently improve following a vomit or a bowel movement
  • The child sometimes has a sausage shaped abdominal mass and is occasionally described as having ‘redcurrent jelly’ stools

Very early onset inflammatory bowel disease

  • Presents before 6 years old
  • Progresses more rapidly than when IBD occurs in older children and is less likely to respond to standard therapies

Infectious colitis

  • Consider if there is a history of a diarrhoeal outbreak for example in a school or nursery
  • Commonly shigella, salmonella, campylobacter and Escherichia (E.coli 0157 will be discussed later)
  • Giardia and Entamoeba histolytica if there is a travel history

Learning bite

If there is a history of antibiotic use consider Clostridium difficile as a cause of colitis.

Juvenile polyps

  • These are submucosal growths with a prevalence of 7-12%, most commonly found in boys below 10 years old
  • Produce haematochezia and occasional abdominal pain
  • Rarely malignant, more commonly an inflammatory process

Foreign body

  • This could have been swallowed or inserted into the rectum
  • Beware button batteries or “super strong” magnets which can erode through gut mucosa causing bleeding, or objects with sharp edges which can cause trauma

Immunoglobulin A deficiency, or Henoch Schonlein Purpura (HSP)

  • A systemic vasculitis which most commonly presents between the ages of 3-15
  • Presents with cutaneous purpura, arthralgia and abdominal pain
  • Can also produce LGIB

Haemolytic Uraemic Syndrome

  • A complication of E.coli 0157:H7 which produces a toxin that can result in HUS
  • A triad of microangiopathic haemolytic anaemia, thrombocytopaenia and acute renal injury
  • Develops 5-10 days after the onset of diarrhoea

Solitary rectal ulcer syndrome

  • Ulceration within the rectum which can be chronic resulting in bright red blood in the stool and pain on defaecation

Inflammatory bowel disease

  • Can be divided into ulcerative colitis which affects only the colon, and Crohn’s disease which only affects the GI tract.
  • Presents with abdominal pain and diarrhoea – with or without blood


  • More common in older adolescents
  • Frequently associated with constipation

Firstly, assess the child for signs of haemodynamic instability, using an A-E approach, and resuscitate as required.


Use the history to gauge the severity of the problem, whether the child is at risk of haemodynamic instability, and to find any clues which could suggest the cause of the bleeding.

  • Colour of stool – bright red/black or tarry
  • Is it definitely blood? – have they recently eaten anything which could cause discoloured stool?
  • Is it definitely from the GI tract? – consider haemoptysis or epistaxis as causes for blood passing through the GI tract
  • Quantity of blood
  • Any other GI symptoms – diarrhoea, vomiting, abdominal pain
  • Any systemic upset – lethargy, weight loss
  • Any other evidence of bleeding disorder – bruising easily/petechiae
  • Recent travel
  • Other medications – NSAIDs, anticoagulants
  • Potential ingestion of harmful substances which could cause bleeding
  • Trauma
  • Co-morbidities e.g. liver disease
  • Family history of GI disorders which could cause LGIB e.g. inflammatory bowel disease


Use the examination to look for signs of anaemia, which would prompt further investigations, bowel obstruction, which is a medical emergency, or any other indicators of the cause of the bleeding.

  • Start with A-E assessment, importantly checking cardiovascular stability considering hypotension/tachycardia/prolonged CRT to be signs of significant blood loss and an indication that the patient needs rapid resuscitation.
  • Check skin for pallor, abnormal bruising or petechiae and jaundice
  • ENT examination for evidence of bleeding, check oral mucosa for ulceration
  • Abdominal examination for any distension, pain on palpation, masses (think sausage shaped mass for intussusception) or organomegaly
  • Perianal examination, assessing for anal fissures, external haemorrhoids or abscesses, evidence of nappy rash which could result in blood being found in the nappy
  • A per rectum examination is rarely indicated in children in the emergency department

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In the majority of cases the history and examination should give you enough information to make a diagnosis.

A study8 printed in the October edition of the Archive of Diseases in Childhood (mentioned already under the ‘Context’ heading), found that over a 2-year period, of 80 children who presented to a tertiary UK hospital with LGIB, 76% of them were diagnosed with constipation or gastroenteritis, and only 5% of them required urgent investigation.

The table below shows investigations that could be considered following specialty review. (Click on the table to enlarge it)

The management of children presenting with LGIB to the emergency department is of course hugely dependent on clinical assessment of the child and what the suspected cause of the bleeding is. Following A-E assessment, if the child is in hypovolaemic shock with a lower GI bleed then resuscitation will be required:

  • Insert 2 large bore cannulae and take bloods: FBC, U&E, CRP, Coagulation, LFTs, group and save, and a VBG
  • Initial fluid bolus of 10ml/kg, consider resuscitating with blood if available
  • Reassess and repeat fluid bolus as indicated
  • If they remain shocked, give 5ml/kg packed red cells as boluses alongside FFP at a 1:1 ratio
  • If still shocked after 20ml/kg blood products then give 10ml/kg platelets and 0.1 ml/kg 10% calcium chloride8 – as always follow your local Trust guidance

Following initial assessment and stabilisation then the history and examination can be taken. This will help determine whether the child requires admission, or whether they can be discharged and if an outpatient appointment is required.

Acute abdomen Inpatient surgical referral
Intermittent blood in stool  Gastroenterology referral for consideration of a Meckel’s scan, or colonoscopy to assess for rectal ulcer, polyps or colitis
Bloody diarrhoea Consider infectious colitis vs IBD, paediatric referral as inpatient or outpatient, depending on clinical assessment

Learning bite

The two instances of LGIB that present most commonly to the emergency department are constipation resulting in anal fissures or haemorrhoids, and infectious gastroenteritis.

If an anal fissure or haemorrhoids are found it is likely there is an underlying diagnosis of constipation. Take a history of stool frequency and type of stool passed and consider starting a laxative. In the case of a child with infectious gastroenteritis, the need for admission will be determined by hydration status, and whether NG or IV fluids are indicated.

  • Children presenting to ED with LGIB are most likely to have a benign cause for their bleeding, but keep a high index of suspicion for the rarer more serious causes.
  • Always consider ‘pseudohaematochezia’8 – discolouration of stool by ingested substances e.g. liquorice, beetroot.
  • Beware the button battery or “super strong” magnets9 – always take a thorough history and consider potential for foreign body ingestion.
  1. Mushtaq F, Tudor G et al. Rectal Bleeding in Children – Causes and Investigations. Paediatrics and Child Health. 2014 November 1; 24(11) 491-500.
  2. Metezai H, Evans J et al. Rectal Bleeding Presenting to the Paediatric Emergency Department. Arch Dis Child. 2020 October 25; 105(Supp 1): A81-A82.
  3. Sharma R, Glick Y. Ligament of Treitz. 2021.
  4. Brandt M. Intestinal Malrotation in Children. 2021.
  5. Javid P, Pauli E. Meckel’s Diverticulum. 2021.
  6. Patel N, Kay M. Lower Gastrointestinal Bleeding in Children – Causes and Diagnostic Approach. 2021.
  7. Beattie M, Dhawan A et al. Paediatric Gastroenterology, Hepatology and Nutrition. 2nd Ed. USA: Oxford University Press. 2018.
  8. Advanced Life Support Group. Advanced Paediatric Life Support: A Practical Approach To Emergencies. 6th Ed. UK: Wiley Blackwell. 2016.
  9. Grossman A. Pseudohaematochezia. JAMA. 1979 May 18; 241(20): 2142.