The most common cause for acute bloody diarrhoea in a 10-year-old child is Campylobacter.Note:Campylobacter is the most common bacterial cause of gastroenteritis in the UK. It typically presents with bloody diarrhoea, fever, abdominal pain and vomiting. The primary source of Campylobacter is uncooked poultry. Treatment is generally supportive unless the child is immunosuppressed or the symptoms are persistent.Other options:- E. coli 0157:H7: It causes acute haemorrhagic diarrhoea, usually afebrile. It can lead to haemolytic uremic syndrome (haemolytic anaemia, acute renal failure and thrombocytopenia), which is the commonest cause of acute renal failure in children.- Rotavirus: It rarely causes bloody diarrhoea.- Salmonella and Yersinia: While they can cause bloody diarrhoea, they are much less common compared to Campylobacter.

Pale, bulky, malodorous stools are evidence of fat malabsorption syndrome. The diagnostic test is jejunal biopsy to rule out other differential diagnoses such as celiac disease, giardiasis or Crohn’s disease etc.

Anorexia nervosa is a serious, psychiatric eating disorder characterized by distorted self-image due to which abnormal eating behaviours are adopted. This disorder affects multiple bodily systems, including the gastrointestinal system. The GI manifestations of anorexia are enlarged salivary glands due to purging behaviour, gastritis, gastroparesis, acute gastric dilatation, superior mesenteric artery syndrome, elevated liver transaminases, which cause hepatocyte apoptosis leading to cirrhosis, and steatosis leading to fatty liver. Hepatosplenomegaly is not a recognized complication of anorexia nervosa.

Hirschsprung’s disease is characterized by congenital absence of the autonomic plexus (Meissner’s and Auerbach’s plexus) in the intestinal wall. Usually limited to the distal colon, it can occasionally involve the entire colon or even the small bowel. There is abnormal or absent peristalsis in the affected segment, resulting in continuous spasm of smooth muscle and partial/complete obstruction. This causes accumulation of intestinal contents and dilatation of proximal segment. Skip lesions are highly uncommon. This disease is seen early in life with 15% patients presenting in first month, 60% by 1 year of age and 85% by the age of 4 years. Symptoms include severe and complete constipation, abdominal distension and vomiting. Patients with involvement of ultra-short segments might have mild constipation with intervening diarrhoea. In older children, symptoms include failure to thrive, anorexia, and lack of an urge to defecate. On examination, an empty rectum is revealed with stool palpable high up in the colon. If not diagnosed in time, it can lead to Hirschsprung’s enterocolitis (toxic megacolon), which can be fulminant and lead to death. Diagnosis involves a barium enema or a rectal suction biopsy. Barium enema shows a transition in diameter between the dilated, normal colon proximal to the narrowed, affected distal segment. It is to be noted that barium enema should be done without prior preparation, which can dilate the abnormal segment, leading to a false-negative result. A 24-hour post-evacuation film can be obtained in the neonatal period -if the colon is still filled with barium, there is a high likelihood of Hirschsprung’s disease. Full-thickness rectal biopsy is diagnostic by showing the absence of ganglion cells. Acetylcholinesterase staining can be done to highlight the enlarged nerve trunks. Abnormal innervation can also be demonstrated by rectal manometry.

People with Gilbert syndrome have a build-up of unconjugated bilirubin in their blood (unconjugated hyperbilirubinemia). In affected individuals, bilirubin levels fluctuate and very rarely increase to levels that cause jaundice. Gilbert syndrome is usually recognized in adolescence. If people with this condition have episodes of hyperbilirubinemia, these episodes are generally mild and typically occur when the body is under stress, for instance because of dehydration, prolonged periods without food (fasting), illness, vigorous exercise, or menstruation. Some people with Gilbert syndrome also experience abdominal discomfort or tiredness. However, approximately 30 percent of people with Gilbert syndrome have no signs or symptoms of the condition and are discovered only when routine blood tests reveal elevated unconjugated bilirubin levels.

The patient has bloody diarrhoea that sounds like a food poisoning in the clinical scenario. Campylobacter is the most common cause of this in the United Kingdom. This is then followed by Salmonella and Shigella. The symptoms are usually self limiting. This is more likely to be bacterial from the food than a viral gastroenteritis.

The boy needs re-hydration and hydro-electrolytic re-balancing due to fluid losses from the gastroenteritis and subsequent dehydration.

This patient has Wilson’s disease. They Kayser-Fleischer ring (ring that encircles the iris) is diagnostic of this. Low serum copper is seen in Wilson’s disease. With the Kayser-Fleischer ring, this makes all of the other answer choices incorrect.

Breast milk jaundice is associated with breast-feeding. It typically occurs one week after birth and can sometimes last up to 12 weeks, but it rarely causes complications in healthy, breast-fed infants. The exact cause of breast milk jaundice isn’t known. However, it may be linked to a substance in the breast milk that prevents certain proteins in the infant’s liver from breaking down bilirubin. The condition may also run in families. Breast milk jaundice is rare, affecting less than 3 percent of infants. When it does occur, it usually doesn’t cause any problems and eventually goes away on its own. It is safe to continue breast-feeding.

Gastroesophageal reflux occurs in almost all infants, manifesting as wet burps after feeding. The spit-ups appear effortless and not particularly forceful.Infants in whom reflux has caused GERD have additional symptoms, such as irritability, feeding refusal, and/or respiratory symptoms such as chronic recurrent coughing or wheezing and sometimes stridor. Much less commonly, infants have intermittent apnoea or episodes of arching the back and turning the head to one side (Sandifer syndrome). Infants may fail to gain weight appropriately or, less often, lose weight.Incidence of gastroesophageal reflux increases between 2 months and 6 months of age (likely due to an increased volume of liquid at each feeding) and then starts to decrease after 7 months. Gastroesophageal reflux resolves in about 85% of infants by 12 months and in 95% by 18 months.

The initial symptoms of spasmodic abdominal pain, rectal bleeding and vomiting might point towards intussusception, but the peak incidence is in children aged 6-9 months. Considering that this child has additional symptoms of haematuria, proteinuria and a purpuric rash, it is more likely that the child has Henoch-Schonlein purpura (HSP). HSP is an identifiable cause of intussusception. It is an IgA-mediated, autoimmune hypersensitivity vasculitis that targets the small vessels of the skin, GI tract, kidneys, and joints. It is most commonly seen in children aged 3 – 6years and is twice as common in boys than girls. Preceding viral URTI with low-grade pyrexia is common. The most common organism associated with HSP is, however, Group A streptococcal infection. A purpuric rash is seen on the back of the legs and buttocks and can less frequently, affect the arms. Arthralgia is common (usually knees/ankles) in these patients. Abdominal pain and bloody diarrhoea may occur. And half of the children with HSP have renal involvement. Rarely, it can lead to end-stage renal failure. Treatment includes adequate hydration, occasionally steroids, and other immunosuppressants. The disease can recur in 1 in 3 children.

Bulimia nervosa is an eating disorder that involves frequent episodes of binge eating followed by inappropriate purging behaviour. The underlying reason for this behaviour is distorted self-image. Bulimia leads to several medical issues, including various laboratory derangements. Among these deranged laboratory parameters are the hormone cholecystokinin, which is found to be decreased in women having bulimia. It is hypothesized that the bingeing episodes observed in patients with bulimia are due to lower levels of CCK since normal levels of CCK are involved in maintaining satiety and controlling the urge to binge eat.

Most experts suggest that parents reassurance in case of infantile gastro-oesophageal reflux (GOR) is a sufficient initial measure that involves education about regurgitation and lifestyle changes.

Based on the clinical scenario, the most probable diagnosis for this patient is pancreatitis.Although rare in childhood, the presence of abdominal pain radiating to the back with shock and tachycardia, and a raised amylase, should raise a suspicion of pancreatitis. Possible causes include trauma, drugs, viral illness, mumps, hyperparathyroidism, hyperlipidaemia and cystic fibrosis. Other options:- Normal LFTs in this patient make hepatitis unlikely. – Gastroenteritis with severe diarrhoea and vomiting may account for the shock and tachycardia, but guarding on abdominal examination and the raised amylase would not be explained by gastroenteritis. – Pregnancy is an important diagnosis to consider in an adolescent with abdominal pain, but the raised amylase and other features point to a diagnosis of pancreatitis.

Projectile vomiting is the hallmark symptom of hypertrophic pyloric stenosis. It is the most common cause of intestinal obstruction in infancy, which has a male-to-female predominance of 4-5:1. Current management recommendations include ultrasonography for diagnosis, correction of electrolytes, and surgical intervention.

Food poisoning is defined as an illness caused by the consumption of food or water contaminated with bacteria and/or their toxins, or with parasites, viruses, or chemicals. The most common pathogens are Norovirus, Escherichia coli, Salmonella, Clostridium perfringens, Campylobacter, and Staphylococcus aureus.The following are some of the salient features of food poisoning:Acute diarrhoea in food poisoning usually lasts less than 2 weeks. Diarrhoea lasting 2-4 weeks is classified as persistent. Chronic diarrhoea is defined by duration of more than 4 weeks.The presence of fever suggests an invasive disease. However, sometimes fever and diarrhoea may result from infection outside the GI tract, as in malaria.A stool with blood or mucus indicates invasion of the intestinal or colonic mucosa.Reactive arthritis can be seen with Salmonella, Shigella, Campylobacter, and Yersinia infections.A profuse rice-water stool suggests cholera or a similar process.Abdominal pain is most severe in inflammatory processes. Painful abdominal cramps suggest underlying electrolyte loss, as in severe cholera.A history of bloating should raise the suspicion of giardiasis.Yersinia enterocolitis may mimic the symptoms of appendicitis.Proctitis syndrome, seen with shigellosis, is characterized by frequent painful bowel movements containing blood, pus, and mucus. Tenesmus and rectal discomfort are prominent features.Consumption of undercooked meat/poultry is suspicious for Salmonella, Campylobacter, Shiga toxin E coli, and C perfringens.Consumption of raw seafood is suspicious for Norwalk-like virus, Vibrioorganism, or hepatitis A.Consumption of homemade canned foods is associated with C botulinum.Consumption of unpasteurized soft cheeses is associated with Listeria, Salmonella, Campylobacter, Shiga toxin E coli, and Yersinia.Consumption of deli meats notoriously is responsible for listeriosis.Consumption of unpasteurized milk or juice is suspicious for Campylobacter, Salmonella, Shiga toxin E coli, and Yersinia.Salmonella has been associated with consumption of raw eggs.

Coeliac disease is associated with the following conditions:- Dermatitis herpetiformis- Autoimmune disorders (e.g. thyroid disease, pernicious anaemia, diabetes)- IgA deficiency- Small-bowel malignancy, particularly lymphoma, if the gluten-free diet is not followed.Serology testing: The IgA tissue transglutaminase antibody is the most sensitive and specific, compared with the anti-endomysial antibody. However, false negatives will occur in children who are IgA-deficient, and IgA levels should be taken at the same time. Other options:Distal obstruction syndrome, meconium ileus, pancreatitis and rectal prolapse are all gastrointestinal manifestations of cystic fibrosis.

Pyloric stenosis affects infants, typically in the second to fourth weeks of life and is caused most commonly by hypertrophy and thickening of the pylorus. It usually presents with projectile vomiting and failure to thrive. The infant usually has a normal appetite. Features include: ‘projectile’ vomiting, typically 30 minutes after a feed, constipation and dehydration may also be present and a palpable mass may be present in the upper abdomen.

The gastrocolic reflex is a physiological reflex that involves increase in colonic motility in response to stretch in the stomach and by-products of digestion in the small intestine. It is shown to be uneven in its distribution throughout the colon, with the sigmoid colon affected more than the right side of the colon in terms of a phasic response. Various neuropeptides have been proposed as mediators of this reflex, such as serotonin, neurotensin, cholecystokinin and gastrin.

Based on the history and clinical presentation, she most likely has iron toxicity.Iron can cause scarring of the gut mucosa. This explains her pyloric stenosis. This typically occurs at the pylorus as this is where iron tablets tend to pool and cause maximal tissue damage.Other options:- Citalopram: Selective serotonin reuptake inhibitors (SSRIs) ingestion rarely causes serious consequences. It can rarely lead to serotonin syndrome (autonomic instability, mental status change, and increased neuromuscular tone).- Ibuprofen: While it may cause gastritis, ibuprofen does not cause pyloric/intestinal stenosis.- Thyroxine: An overdose of thyroxine will cause features of hyperthyroidism which are not present in the patient in question.- Zinc: High doses of zinc can cause abdominal cramps, nausea, vomiting and diarrhoea.

Polycythaemia is a condition in which there is an increased red cell mass and increasing blood viscosity, which decreases its ability to flow. It is not associated with food allergies, but is fundamentally caused by either an overproduction of red blood cells, or a reduction in the volume of plasma. Abdominal pain, constipation, loose and frequent stools, and pallor are all non IGE mediated symptoms of food allergy according to NICE guidelines in the UK.

Based on the given scenario, the most probable diagnosis for this patient is acquired immune deficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV). Thus, the most appropriate investigation to confirm the underlying pathology in this patient would be viral serology. Rationale:The presence of oesophageal candidiasis is highly suggestive of severe immunosuppression. The causes of immunosuppression can be chemotherapy, with haematological malignancy, HIV or inhaled steroids. In patients with HIV, oesophageal candidiasis is part of the spectrum of AIDS-defining illnesses and usually occurs when the CD4 count is < 200 cells/microL. Other AIDS-defining illnesses include PCP pneumonia and CMV infections.Oesophageal Candidiasis:It is characterised by white spots in the oropharynx with extension into the oesophagus. It seldom occurs without an associated underlying risk factor like broad-spectrum antibiotic usage, immunosuppression and immunological disorders.Patients may present with oropharyngeal symptoms, odynophagia and dysphagia.Treatment is directed both at the underlying cause (which should be investigated for) and with oral antifungal agents.

CUTANEOUS DISORDERS OR DERMATOSIS ASSOCIATED WITH IBD- Psoriasis- Secondary amyloidosis- Vitiligo- Acquired epidermolysis bullosaIn some cases, non-granulomatous skin disorders occur as a reaction to the intestinal disease. These include:- Pyoderma gangrenosum- Neutrophilic dermatosis / Sweet syndrome, typically with pustules- Pyodermatitis-pyostomatitis vegetans, a purulent erosive dermatosis characterised by snail-track ulcers- Erythema multiforme- Erythema nodosum- Acneiform eruptions including nodulocystic acne, hidradenitis suppurativa and folliculitis- Palisaded neutrophilic and granulomatous dermatitis- Necrotizing and granulomatous small vessel vasculitis.

The main problem with infants having gastroenteritis is dehydration. So they should be admitted to the hospital for IV fluids if they are not tolerating oral fluids.

Breast milk jaundice is thought to be associated with one or more abnormalities in the maternal milk itself. Breast milk jaundice syndrome generally needs no therapy if serum bilirubin concentrations remain below 270 mmol/l in healthy full-term infants. When the serum bilirubin concentration is above 270 mmol/l and rising, temporary interruption of breastfeeding may be indicated.

One of the features of pyloric stenosis is hypochloraemic, hypokalaemic metabolic alkalosis. In emergency settings, capillary blood gas is the easiest and fastest way to establish a sustainable suspicion of pyloric stenosis. However, all tests are useful for the diagnosis of the condition.

The most probable diagnosis in this patient is lead poisoning.Lead poisoning: While it is not common, it can be potentially fatal. One of the key presenting features here is pica, the ingestion of non-nutritive substances such as soil, soap, paper or wood. Pica can also be observed in children in iron-deficiency anaemia, developmental delay and pregnancy. However, in a child who is exposed to lead in their environment (e.g. from lead paint or pipes), lead poisoning is most likely. It is commonly associated with iron deficiency which in turn increases the lead absorption. Treatment is either with oral D-penicillamine or intravenous sodium calcium edetate.

Total parenteral nutrition (TPN) frequently causes derangement of liver function in children. Other options:- While line sepsis and thromboembolism are recognised complications of TPN, they do not occur frequently. – A child who is on TPN will require regular blood tests because of the potential for the development of electrolyte abnormalities. Need to observe their liver function, in order to provide TPN more accurately.

Intussusception is the most suggested case here based on the child’s symptoms. The urgent course of treatment is to bring the child to a paediatric surgical unit. If air reduction attempts fail, surgery will have to be done. Risk factors for intussusception include viral infection and intestinal lymphadenopathy.

In pyloric stenosis a new-born baby presents with a history of vomiting, constipation and deranged electrolytes. Excessive vomiting leads to hypokalaemia. Difficulty in food passing from the stomach to the small intestine causes constipation. Hypokalaemia also causes constipation. None of the other disorders mentioned present with the hypokalaemia, vomiting and constipation triad in a new-born.