Celiac disease has characteristic shortened intestinal villi. When patients with celiac disease eat products containing gluten, they are unable to absorb the nutrients due to flattened or shortened intestinal villi. The blistering rash present on the patient’s elbows strongly suggests celiac disease. This rash is a sign of the condition Dermatitis Herpetiformis which is associate with celiac disease. Therefore, it is also often called ‘gluten rash’.

The coeliac axis supplies the liver and stomach and from the oesophagus to the first half of the duodenum. The second half of the duodenum to the first two thirds of the transverse colon is supplied by the superior mesenteric artery. The inferior mesenteric supplies the last third of the transverse colon (approximately from the splenic flexure) to the first third of the rectum. The last two thirds of the rectum are supplied by the middle rectal artery. The greater curvature of the stomach is supplied by branches of the splenic artery, which itself comes from the coeliac axis.

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.

Pellagra occurs as a result of niacin (vitamin B-3) deficiency. Niacin is required for most cellular processes. Since tryptophan in the diet can be converted to niacin in the body, both of these need to be deficient for pellagra to develop.The classical triad of symptoms is diarrhoea, dermatitis and dementia.The first sign is reddened skin with superficial scaling in areas exposed to sunlight, heat and friction. This may resemble severe sunburn then gradually subsides leaving a dusky brown-red colouration. The rash is usually symmetrical with a clear edge between affected and unaffected skin.

Pale stools suggest obstructive jaundice. Initially, the symptoms of biliary atresia are indistinguishable from those of neonatal jaundice, a usually harmless condition commonly seen in infants. However, infants with biliary atresia develop progressive conjugated jaundice, pale white stools and dark urine.

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.

The Green Book guidelines report in an active infection (HBeAg+ and HBsAg+) to give the vaccine as well as immunoglobulin. If antibodies are present it is not active infection (anti-Hbe) and then in that case only the vaccine, and no immunoglobulin, would be given. The presence of HBeAg means a person is infectious and can transmit to other people.

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.

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 structure in question is the rectus sheath. This sheath encloses the rectus abdominis muscle and thus, will be encountered by the surgeon.Note:- Midline incision: It is the most common approach to the abdomen. The structures divided during this incision are linea alba, transversalis fascia, extraperitoneal fat, and peritoneum ( with care taken to avoid the falciform ligament above the umbilicus).The bladder can be accessed via an extraperitoneal approach through the space of Retzius.- Paramedian incision: It is an incision that is made parallel to the midline. The structures divided or retracted are anterior rectus sheath, rectus (retracted), posterior rectus sheath, transversalis fascia, extraperitoneal fat, and peritoneum.- Battle incision: It is similar to a paramedian but the rectus is displaced medially (and thus denervated).- Kocher’s incision: It is an incision made under the right subcostal margin, e.g. cholecystectomy (open).- Lanz incision: It is an incision in the right iliac fossa, e.g. appendicectomy.Gridiron incision: It is an oblique incision centred over the McBurney’s point – usually used for appendicectomy (less cosmetically acceptable than LanzPfannenstiel’s incision: It is a transverse suprapubic incision, primarily used to access pelvic organs.McEvedy’s incision: It is a groin incision used for emergency repair strangulated femoral hernia.Rutherford Morrison incision: It provides an extraperitoneal approach to left or right lower quadrants. It provides excellent access to iliac vessels and is the approach of choice for first-time renal transplantation.