Rectal bleeding in children is less common than in adults and different causes are likely depending on the age of the child and associated clinical features.¹ It can cause a great deal of anxiety amongst parents and this requires appropriate assessment, explanation and reassurance. It requires accurate assessment for correct diagnosis and management just as for adults. The vast majority of rectal bleeding in children is benign but it may nevertheless indicate serious underlying pathology.

Epidemiology

The incidence and prevalence of rectal bleeding in children are surprisingly poorly documented. The epidemiology of some of the underlying causes is better known in some cases. Certain causes such as anal fissure are common in general practice. Overall it is not a common presentation in children attending hospital.

Presentation

History and examination

The history and examination should be appropriate for age and the likely aetiology. A general guide is outlined in the box below:

• Anal fissures:
  • Occur in neonates and infants but also in older children.
  • Bright blood and pain are features of this condition.
• Necrotising enterocolitis:
  • Occurs in neonates.
  • Recurrent bleeding in an infant recovering from this condition may indicate recurrence or stricture.
• Volvulus:
  • Can occur in neonates and infants.
  • In neonates, it is heralded by sudden onset of melaena and bilious vomiting.
  • In infants, volvulus can also occur and presenting features include vomiting and abdominal distension.
  • Rectal bleeding occurs relatively late with development of gangrenous bowel.
• Intussusception:
  • Occurs most often between 6 and 18 months.
  • Pain, distension, vomiting and a sausage-shaped mass are characteristic, as is the passage of blood and mucus in the form of redcurrant jelly stool.
• Milk protein allergy:
  • Can cause occult or overt rectal bleeding.
  • It is also associated with diarrhoea, weight loss, vomiting and general irritability.
  • Symptoms resolve when the offending milk product is withdrawn.
• Polyps:
  • Generally, these cause painless recurrent bleeding.²
  • In infants and up to teenage years they are most often juvenile polyps which autoamputate and usually require no treatment.
  • Other polyposis syndromes are diagnosed at colonoscopy.
• Meckel's diverticulum:
  • Occurs in about 2% of the population (2 feet from the caecum and 2 inches in length) and commonly presents before age 4 years, often with quite brisk rectal bleeding.
  • It is a remnant of the vitellointestinal duct and, apart from bleeding, can present in a variety of other ways or remain symptomless.
  • Can also cause melaena at about age 10 years.
• Inflammatory bowel disease (IBD):
  • This starts to become more common over the age of 2 years.
  • Bleeding occurs less often with Crohn's disease than with ulcerative colitis, but both can cause bloody diarrhoea.
  • Rectal bleeding usually occurs in children known to have IBD rather than as a presenting feature of the IBD.
• Infectious diarrhoea:
  • Includes that caused by Clostridium difficile and causes bleeding associated with profuse diarrhoea.
  • Gastroenteritis in many varieties (more commonly Campylobacter spp.).
• Vascular lesions:
  • Includes a range of haemangiomas, arteriovenous malformations and malformations which can be difficult to detect even with new techniques.
  • Colonoscopy and arteriography are used to localise bleeding.

Differential diagnosis

The likely causes in children vary with age.¹ The table attempts to illustrate the changing frequency of different conditions with age. It is difficult to be precise about the relative frequency of different causes in different age groups because of the varying methodologies and age groups in studies done.

Causes in adolescents

In adolescents, the pattern of disease and the possible causes begin more to resemble the pattern in adults. Lower gastrointestinal bleeding is most often caused by:

• Anal fissures and haemorrhoids
• Colonic polyps
• Gastroenteritis
• Inflammatory bowel disease (IBD)

Rare and unusual causes

Rare causes need to be considered. Again, how rare a particular cause is can vary with age. It is sometimes necessary to consider upper gastrointestinal bleeding (including all causes such as drugs, gastrooesophageal reflux, stress ulcers, etc.) as a cause for rectal bleeding, as for adults. The shorter transit time in children makes this particularly worthy of consideration where a lower gastrointestinal cause is not obvious and in ill children with massive bleeding.

Sexual abuse in children may present with rectal bleeding, and unusual features in the history and examination may alert clinicians and nurses to this possibility.

Investigations

Most cases of rectal bleeding in children are benign and self-limiting.¹ The majority of cases will not require any investigation. When bleeding is substantial or recurrent consider:

• Full blood count. This would, for example, reveal anaemia or thrombocytopenia.
• Clotting studies. This should be considered when a clotting disorder is suspected or needs to be excluded.
• Liver function tests. These should be checked where history or examination suggests liver disease.
• Imaging is not usually necessary or helpful but may be necessary where more unusual causes of bleeding need to be excluded (in ill children or children with substantial or recurrent bleeding).

Management

The management will depend on the cause and extent of bleeding. The history and examination should reveal the extent of bleeding. As most cases will be simple, self-limiting and benign management will focus on explanation, reassurance and 'safety-netting'. When bleeding is profuse or recurrent then management will focus on resuscitation, investigation and then treatment of the cause.

Document references

1. Raine PA; Investigation of rectal bleeding. Arch Dis Child. 1991 Mar;66(3):279-80.
2. Durno CA; Colonic polyps in children and adolescents. Can J Gastroenterol. 2007 Apr;21(4):233-9. [abstract]

Acknowledgements