GI Illness Flashcards
How common is constipation in children?
Constipation in children is a very common problem in paediatrics. Most cases of constipation can be described as idiopathic constipation or functional constipation, meaning there is not a significant underlying cause other than simple lifestyle factors. It is important to think about possible secondary causes of constipation, such as Hirschsprung’s disease, cystic fibrosis or hypothyroidism.
How does constipation present?
How often someone opens their bowels varies between individuals. This is even more variable in breast-fed babies, which can have as little as one stool a week. Someone opening their bowels daily may be constipated, whereas someone opening their bowels twice a week may not, if that is normal for them.
Typical features in the history and examination that suggest constipation are:
Less than 3 stools a week
Hard stools that are difficult to pass
Rabbit dropping stools
Straining and painful passages of stools
Abdominal pain
Holding an abnormal posture, referred to as retentive posturing
Rectal bleeding associated with hard stools
Faecal impaction causing overflow soiling, with incontinence of particularly loose smelly stools
Hard stools may be palpable in abdomen
Loss of the sensation of the need to open the bowels
What is encopresis and what causes it?
Encopresis is the term for faecal incontinence. This is not considered pathological until 4 years of age. It is usually a sign of chronic constipation where the rectum becomes stretched and looses sensation. Large hard stools remain in the rectum and only loose stools are able to bypass the blockage and leak out, causing soiling.
Other rarer causes of encopresis include:
Spina bifida Hirschprung’s disease Cerebral palsy Learning disability Psychosocial stress Abuse
Which lifestyle factors can contribute to the development of constipation?
There are a number of lifestyle factors that can contribute to the development and continuation of constipation:
Habitually not opening the bowels Low fibre diet Poor fluid intake and dehydration Sedentary lifestyle Psychosocial problems such as a difficult home or school environment (always keep safeguarding in mind)
What is desensitisation of the rectum and how does this cause problems?
Often patients develop a habit of not opening their bowels when they need to and ignoring the sensation of a full rectum. Over time they loose the sensation of needing to open their bowels, and they open their bowels even less frequently. They start to retain faeces in their rectum. This leads to faecal impaction, which is where a large, hard stool blocks the rectum. Over time the rectum stretches as it fills with more and more faeces. This leads to further desensitisation of the rectum. The longer this goes on, the more difficult it is to treat the constipation and reverse the problem.
Name some secondary causes of constipation.
Hirschsprung’s disease Cystic fibrosis (particularly meconium ileus) Hypothyroidism Spinal cord lesions Sexual abuse Intestinal obstruction Anal stenosis Cows milk intolerance
Which features would make you suspect a more serious cause of constipation?
Red flags are things in the history or examination that should make you think about serious underlying conditions that may be causing the constipation. These should prompt further investigations and referral to a specialist:
Not passing meconium within 48 hours of birth (cystic fibrosis or Hirschsprung’s disease)
Neurological signs or symptoms, particularly in the lower limbs (cerebral palsy or spinal cord lesion)
Vomiting (intestinal obstruction or Hirschsprung’s disease)
Ribbon stool (anal stenosis)
Abnormal anus (anal stenosis, inflammatory bowel disease or sexual abuse)
Abnormal lower back or buttocks (spina bifida, spinal cord lesion or sacral agenesis)
Failure to thrive (coeliac disease, hypothyroidism or safeguarding)
Acute severe abdominal pain and bloating (obstruction or intussusception)
What complications arise from constipation?
Pain Reduced sensation Anal fissures Haemorrhoids Overflow and soiling Psychosocial morbidity
How can constipation be managed?
A diagnosis of idiopathic constipation can be made without investigations, provided red flags are considered. It is important to provide adequate explanation of the diagnosis and management as well as reassure parents about the absence of concerning underlying causes. Explain that treating constipation can be a prolonged process, potentially lasting months.
NICE clinical knowledge summaries recommend:
Correct any reversible contributing factors, recommend a high fibre diet and good hydration Start laxatives (movicol is first line) Faecal impaction may require a disimpaction regimen with high doses of laxatives at first Encourage and praise visiting the toilet. This could involve scheduling visits, a bowel diary and star charts. Laxatives should be continued long term and slowly weaned off as the child develops a normal, regular bowel habit.
How does the pyloric sphincter work?
The pyloric sphincter is a ring of smooth muscle the forms the canal between the stomach and the duodenum. Hypertrophy (thickening) and therefore narrowing of the pylorus is called pyloric stenosis. This prevents food traveling from the stomach to the duodenum as normal.
After feeding, there is increasingly powerful peristalsis in the stomach as it tries to push food into the duodenum. Eventually it becomes so powerful that it ejects the food into the oesophagus, out of the mouth and across the room. This is called “projectile vomiting”.
How does pyloric stenosis present?
Pyloric stenosis typically presents in the first few weeks of life, with a hungry baby that is thin, pale and generally failing to thrive. The classic description of vomiting you should remember for your exams is “projectile vomiting”.
If examined after feeding, often the peristalsis can be seen by observing the abdomen. A firm, round mass can be felt in the upper abdomen that “feels like a large olive”. This is caused by the hypertrophic muscle of the pylorus.
Blood gas analysis will show a hypochloric (low chloride) metabolic alkalosis as the baby is vomiting the hydrochloric acid from the stomach. This is a common data interpretation question in exams, so worth remembering.
How is pyloric stenosis managed?
Diagnosis is made using an abdominal ultrasound to visualise the thickened pylorus.
Treatment involves a laparoscopic pyloromyotomy (known as “Ramstedt’s operation“). An incision is made in the smooth muscle of the pylorus to widen the canal allowing that food to pass from the stomach to the duodenum as normal. Prognosis is excellent following the operation.
What is gastroenteritis?
Acute gastritis is inflammation of the stomach and presents with nausea and vomiting. Enteritis is inflammation of the intestines and presents with diarrhoea. Gastroenteritis is inflammation all the way from the stomach to the intestines and presents with nausea, vomiting and diarrhoea.
Gastroenteritis is a very common condition in children. The most common cause of gastroenteritis is viral. It is very easily spread and patients presenting with gastroenteritis often have an affected family member or contact.
What is important to remember in gastroenteritis?
It is essential to isolate the patient in any healthcare environment, such as a paediatric assessment unit or hospital ward, as they can easily spread it to other patients.
Dehydration is the main concern. The key to management is establishing whether they are able to keep themselves hydrated or whether they need admission for IV fluids. Antibiotics are generally not recommended or required. Most children make a full recovery with simple supportive management, but beware gastroenteritis can potentially be fatal, especially in very young or vulnerable children with other health conditions.
What differentials other than gastroenteritis would you consider in diarrheoa cases?
Loose stools are a common complaint and not all cases are caused by gastroenteritis. Stools from normal babies can vary from loose stools several times a day to one stool per week. Steatorrhoea means greasy stools with excessive fat content. This suggests a problem with digesting fats, such as pancreatic insufficiency (think about cystic fibrosis).
Key conditions to think about in patients with loose stools are:
Infection (gastroenteritis) Inflammatory bowel disease Lactose intolerance Coeliac disease Cystic fibrosis Toddler’s diarrhoea Irritable bowel syndrome Medications (e.g. antibiotics)
What are the common causes of viral gastroenteritis?
Viral gastroenteritis is common. It is highly contagious. Common causes are:
Rotavirus
Norovirus
Adenovirus is a less common cause and presents with a more subacute diarrhoea.
How does e.coli cause gastroenteritis?
Escherichia coli (E. coli) is a normal intestinal bacteria. Only certain strains cause gastroenteritis. It is spread through contact with infected faeces, unwashed salads or contaminated water.
E. coli 0157 produces the Shiga toxin. This causes abdominal cramps, bloody diarrhoea and vomiting. The Shiga toxin destroys blood cells and leads to haemolytic uraemic syndrome (HUS).
The use of antibiotics increases the risk of haemolytic uraemic syndrome, therefore antibiotics should be avoided if E. coli gastroenteritis is considered.
How does campylobacter cause gastroenteritis?
Campylobacter is a common cause of travellers diarrhoea. It is the most common bacterial cause of gastroenteritis worldwide. Campylobacter means “curved bacteria”. It is a gram negative bacteria that has a curved or spiral shape. It is spread by:
Raw or improperly cooked poultry
Untreated water
Unpasteurised milk
Incubation is usually 2 to 5 days. Symptoms resolve after 3 to 6 days. Symptoms are:
Abdominal cramps Diarrhoea often with blood Vomiting Fever Antibiotics can be considered after isolating the organism where patients have severe symptoms or other risk factors such as HIV or heart failure. Popular antibiotic choices are azithromycin or ciprofloxacin.
How does shigella cause gastroenteritis?
Shigella is spread by faeces contaminating drinking water, swimming pools and food. The incubation period is 1 to 2 days and symptoms usually resolve within 1 week without treatment. It causes bloody diarrhoea, abdominal cramps and fever. Shigella can produce the Shiga toxin and cause haemolytic uraemic syndrome. Treatment of severe cases is with azithromycin or ciprofloxacin.
How does salmonella cause gastroenteritis?
Salmonella is spread by eating raw eggs or poultry, or food contaminated with the infected faeces of small animals. Incubation is 12 hours to 3 days and symptoms usually resolve within 1 week. Symptoms are watery diarrhoea that can be associated with mucus or blood, abdominal pain and vomiting. Antibiotics are only necessary in severe cases and should be guided by stool culture and sensitivities.
How does bacillus cereus cause gastroenteritis?
Bacillus cereus is a gram positive rod spread through inadequately cooked food. It grows well on food not immediately refrigerated after cooking. The typical food is fried rice left out at room temperature.
Whilst growing on food it produces a toxin called cereulide. This toxin causes abdominal cramping and vomiting within 5 hours of ingestion. When it arrives in the intestines it produces different toxins that cause a watery diarrhoea. This occurs more than 8 hours after ingestion. All of the symptoms usually resolves within 24 hours.
The typical course is vomiting within 5 hours, then diarrhoea after 8 hours, then resolution within 24 hours.
How does giardia cause gastroenteritis?
Giardia lamblia is a type of microscopic parasite. It lives in the small intestines of mammals. These mammals may be pets, farmyard animals or humans. It releases cysts in the stools of infected mammals. The cysts contaminate food or water and are eaten, infecting a new host. This is called faecal-oral transmission.
Infection may not cause any symptoms, or it may cause chronic diarrhoea. Diagnosis is made by stool microscopy. Treatment is with metronidazole.
How is gastroenteritis managed?
Good hygiene helps prevent gastroenteritis. When patients develop symptoms they should immediately be isolated to prevent spread. Barrier nursing and rigorous infection control is important for patients in hospital to prevent spread to other patients. Children need to stay off school until 48 hours after the symptoms have completely resolved.
A sample of the faeces can be tested with microscopy, culture and sensitivities to establish the causative organism and antibiotic sensitivities.
The key to managing gastroenteritis is to ensure they remain hydrated whilst waiting for the diarrhoea and vomiting to settle. Attempt a fluid challenge. Each hospital will have a policy for this. It involves recording a small volume of fluid given orally every 5-10 minutes to ensure they can tolerate it. If they are able to tolerate oral fluid and are adequately hydrated they can usually be managed at home. Rehydration solutions (e.g. dioralyte) can be used if tolerated. Dehydrated children or those that fail the fluid challenge may require IV fluids.
Once oral intake is tolerated a light diet can be slowly reintroduced. Dry foods such as toast may be better tolerated.
Antidiarrhoeal medication such as loperamide and antiemetic medication such as metoclopramide are generally not recommended. Antidiarrhoeal medications are particularly avoided in e. coli 0157 and shigella infections, and where there is bloody diarrhoea or high fever.
Antibiotics should only be given in patients that are at risk of complications once the causative organism is confirmed.
Which post-gastroenteritis complications may occur?
The are possible post-gastroenteritis complications:
Lactose intolerance
Irritable bowel syndrome
Reactive arthritis
Guillain–Barré syndrome
