GI Board Review:

1. GI Board Review: The important S**T April 13, 2010 Jillian Parekh, MD

2. Question: • A 12 y/o F presents to the ED with abdominal pain. Her parents report that she awakened with a temp of 101 this am, c/o abdominal pain, and has vomited twice. Denies diarrhea, and there are no sick contacts. She reports nausea and no interest in food or drink. She was previously healthy. UA shows SG 1015, otherwise normal. • Of the following, the finding that MOST indicated the need for immediate surgical intervention is: • A. Abdominal distention • B. Hyperactive bowel sounds • C. Pain in the right lower quadrant • D. Rigidity of the abdominal wall • E. Voluntary guarding

3. Answer: • A. Abdominal distention • B. Hyperactive bowel sounds • C. Pain in the right lower quadrant • D. Rigidity of the abdominal wall • E. Voluntary guarding

4. Explanation: • Abdominal tenderness can occur in children with nonsurgical abdomens and those with peritoneal inflammation • Presence of bowel sounds is usually reassuring • Simple abdominal distention may occur with non surgical causes of abodminal pain • RLQ pain is suggestive when other signs of peritonitis are present, but can also occur in other processes (ovarian, AGE) • Voluntary guarding is common on exam, esp with children • Distention with tenderness, rigidity of the abdominal wall to palpation are more specific signs of peritoneal irritation surgical abdomen

5. Appendicitis: • Child > 2 usually • Acute RLQ, periumbilical or midepigastric abdominal pain – classically McBurney’s point • Associated with nausea, vomiting, anorexia, low grade fever • Xray findings: sentinel loop, absence of air in the RLQ

6. NSAID induced dyspepia • NSAIDs inhibit cyclooxygenase (COX) • COX needed for prostaglandin synthesis • Prostaglandins protect the gastric lining • If they describe a patient with rheumatoid condition p/w epigastric pain…think NSAIDs.

7. Frequent causes of acute pain: • Constipation • Adenitis • Mono • Pancreatitis • Hepatitis • Infection (UTI) • Trauma

8. Recurrent or chronic pain: • 3 or more episodes of abdominal pain in more than 3 months • Pain must be severe enough to interrupt normal activity • On the boards, think of psych factors

9. Encorporesis • LLQ pain with a palpable mass on exam • School aged child, soils pants, denies diarrhea, no systemic complaints • Treatment: • Education (avoid blame) • Emptying colon (enema, cathartics, stool softeners) • Maintenance (daily stools)

10. Giardia Lamblia • Several weeks of intermittent watery diarrhea, abdominal distension, anorexia • Afebrile • Hx of drinking bad water on camping trip or daycare exposure • Dx = string test “Entero-Test” via ELISA

11. Diarrhea: • Never give anti-diarrheal in children • Watery diarrhea: derives from small intestine – high volume, non bloody • Inflammatory diarrhea: small and frequently contains blood, mucous and WBCs. More toxic presentation • Continue normal diet • ORT if needed: 2% glucose, 90mEq NaCl • Avoid fatty foods, high glycemic foods • BRAT diet is too limited • No bowel rest – decreasing gut motility can result in pooling of fluids and unnoticed dehydration

12. Viral diarrhea • Rotavirus is the leading cause worldwide • Adenovirus is 2nd leading cause

13. Bacterial Diarrhea • Enteropathogenic E.Coli: • Seen in areas with poor sanitation • p/w fever, vomiting, non-bloody stools • Entertoxigenic E. Coli: • Traveller’s diarrhea • p/w severe diarrhea, cramping • Enterohemorrhagic E. Coli: • Causes HUS • Hemolytic anemia • Thrombocytopenia • Uremia: renal failure • Enteroinvasive: • Stools are blood and mucous tinged, tenesmus • Similar to dysentery

14. Salmonella • Green, malodorous stools • Can present in infancy, unlike shigella • Typhoid fever (S. Typhi) is more invasive form of this disease • p/w fever, HA, abdominal pain, myalgias and rose spots • Treat with Ceftriaxone/Cefotaxime if: • < 3 months • Immunocompromised • Severe colitis

15. Shigella • Present with watery diarrhea and fever, bloody diarrhea usually appears after fever subsides • Increased bandemia on CBC, even if WBC not elevated • Diarrhea + seizure = Shigella • Treat with Bactrim (high resistance)

16. Pseudomembranous Colitis • Presents as diarrhea (often bloody), abdominal pain and vomiting. • Caused by C. Difficile toxin • Often will give hx of prior abx use (Clinda) • Rx: Flagyl PO • Vanco if resistant • Infants can be asymptomatic carriers – rarely become symptomatic even when the toxin is present in stool • Don’t treat < 6 months old (unless sx)

17. Chronic Diarrhea: • Diarrhea that lasts > 2 weeks and can’t be attributed to AGE. • Nutrition and growth often affected • Transient lactase deficiency • Cyrptosporidium • Toddler’s diarrhea • Malnutrition • Abetalipoproteinemia • Intestinal lymphangiectasia

18. Question: • A 10 y/o African American boy presents to clinic c/o a 1 year history of stomach pain, nausea, bloating and diarrhea that occurs 45-60 mins after eating dairy foods. Sx occur only when he eats too much. He denies emesis, hematochezia, or pruritis associated with these episodes. On PE, the boy appears healthy and has normal VS. His abdomen is soft and has normal BS, stool guaiac is negative. • Of the following, the MOST likely cause for the symptom is: • A. allergic eosinophilic gastroenteritis • B. lactose intolerance • C. milk protein allergy • D. milk protein enterocolitis • E. oral allergy syndrome

19. Answer: • A. allergic eosinophilic gastroenteritis • B. lactose intolerance • C. milk protein allergy • D. milk protein enterocolitis • E. oral allergy syndrome

20. Explanation: • Lactose intolerance is consistent as has onset of only GI sx, can tolerate small amounts of dairy, sx occur 30 mins later. Results from decreased lactase activity. In children, lactase activity doesn’t decline to clinically significant levels until age 6. • Milk protein allergy is IgE mediated – develops in first year of life (urticaria, angioedema, AD…). • Milk protein enterocolitis, is non IgE mediated, but p/w hematochezia within first months of life. Usually cross react with soy milk- need elemental formula. • Allergic eosinophilic gastro will always present with element of weight loss or FTT. Usu presents with reflux and dysphagia. • Oral allergy syndrome is a localized reaction that occurs in 10-40% of individuals with allergic rhinitis. Usually occurs with raw fruits or vegetables – causes immediate pruritis and swelling.

21. Milk Issues: • Cow Milk Protein Allergy: only 1% population, usually resolves by age 2. Present with associated sx (AD, Asthma) • Milk Protein Intolerance: • Milk Protein Allergy – IgE mediated, can cause anaphylaxis, can trigger AD • Food Sensitivity – FPIES (Food Protein Enterocolitis Syndrome). More common than IgE form. Causes vomiting and bloody diarrhea. Cow and soy milk are frequent triggers. Rx: elimination diet. -avoid milk products for 1-2 years

22. Neonatal Vomiting

23. Antral Web: • Similar to pyloric stenosis, but outlet obstruction is before the pylorus. • Presents with NON-bilious vomiting • Presents in first 6 mos (later than PS) • Tend to describe low BW and polyhydramnios • Dx: US • Radiolucent filling defect in prepylori region • RX: surgical resection

24. Pyloric Stenosis: • Males > Females • Maternal hx of PS increases the risk more than paternal hx • Presents with progressive non-bilious vomiting • Will mention: projectile vomiting and palpable olive • Presents in first months (1-5 mos) • HYPOCHLOREMIC HYPOKALEMIC METABOLIC ALKALOSIS • vomit HCL (lose acid and chloride) • Volume loss – kidney holds onto Na, dumps K • Dx: US • Pyloric length > 14 mm • Pyloric muscle thickness > 4mm • Rx: Surgical (after electrolyle repletion)

26. Duodenal Atresia: • Bilious vomiting • Presents in 1st day of life • Frequently icteric (decreased enterhepatic circulation) • Plain XRay: • Double Bubble sign • No air distal to the atresia (if complete) • Rx: NT decompression, surgery

28. Question: • A 5 d/o term infant presents to the ED with a h/o bile stained emesis. She is well nourished and hydrated and had an unremarkable course in the WBN. She was discharged at 48 hrs and was breastfeeding, but her mother states that the baby always has vomited. PE reveals an afebrile patient who has normal VS, but no audible bowel sounds. An abdominal XRay shows paucity of bowel gas. • Of the following, the MOST likely diagnosis is: • A. anorectal atresia • B. cystic fibrosis • C. malrotation of the bowel • D. septic ileus • E. tracheoesophageal fistula

29. Answer: • A. anorectal atresia • B. cystic fibrosis • C. malrotation of the bowel • D. septic ileus • E. tracheoesophageal fistula

30. Explanation: • Bilious emesis is always a surgical emergency in the newborn – signifies anatomic or functional obstruction. • No bowel sounds with paucity of gas on XR is concerning for malrotation with midgut volvulus. • Classic xray finding is double bubble sign • If malrotation is not diagnosed quickly, most of small intestine can be lost. • 50% of malro cases that occur in first year of life, will happen in first week, 25% in weeks 1-4, final 25% in 1month-1year. • Anorectal atresia would present with absent or delayed passage of meconium. • TEF usually presents with resp distress or inability to handle oral secretions. • CF can be associated with meconium ileus and delayed passage of meconium • Septic ileus: patient would appear systemically ill.

31. Malrotation: • Surgical emergency • Cecum fails to descend or be fixed to the posterior right abdominal wall. Can rotate causing compression of duodenum and duodenal obstruction • Presents as bilious vomiting, abdominal tenderness & abdominal distension

33. Volvulus: • Presents as bilious vomiting and R sided abdominal distension • Associated with Ladd Bands which constrict the large and small bowel • XRay • Gastric and duodenal dilatation • Decreased intestinal air • Corkscrew appearance of duodenum

35. Annular Pancreas: • Pancreas literally forms a ring around the intestine causing significant obstruction. • History of polyhdramnios (fluid not swallowed effectively in utero)

36. Inborn Errors of Metabolism: • Common cause of vomiting in infancy • Will be afebrile • Look for metabolic acidosis with and increased AG

37. Question: • A 5 month old infant p/w history of vomiting b/w 10-20 times/day. She is growing and developing normally. There is no blood in the vomitus, no resp sx, and no history of apnea. The parents are frustrated and want something done. PE and upper GI results are normal. • Of the following, the MOST accurate statement about this patient is that she: • A. is at increased risk of SIDS • B. is likely to develop an esophageal stricture later in life • C. probably will outgrow the condition by 1 y/o • D. should be referred for a head CT • E. should undergo colonoscopy to r/o eosinophilic esophagitis

38. Answer: • A. is at increased risk of SIDS • B. is likely to develop an esophageal stricture later in life • C. probably will outgrow the condition by 1 y/o • D. should be referred for a head CT • E. should undergo colonoscopy to r/o eosinophilic esophagitis

39. Explanation: • GER described has no signs of pathologic reflux (recurrent pneumonia, hematemesis, or FTT), so likely that she will outgrow her sx by age 1. • GER occurs in about 50% of term infants and peaks b/w 4-6 months. By 12 mos the GER resolves in 90-95% of infants. • GER rarely causes esophageal strictures • No evidence that GER places you at greater risk for SIDS • Head CT not warranted at this time • Eosinophilic esophagitis should only be considered if strong atopic history

40. GER: • Regurgitation or spitting up, increases when infant lying down • Can present with severe emesis, FTT, or apnea in newborn period • Usually presents around 2 months of age • Uncomplicated GER resolves by age 2 without intervention • Vomiting is effortless, no other signs of illness • Sandifer Syndrome: unusual dystonic movements of the head and neck along with GER • RX: limited to those with symptomatic disease and those with neurologic impairment • Antacids • H2 blockers • PPI

41. Other causes of vomiting: • DKA • Cyclic vomiting- emotional overtones, also at risk for migraines and IBS. Schol aged patient, episodes separated by asx periods, dx of exclusion • Munchausen Syndrome By Proxy • Rumination: frequent regurgitation of ingested food into the mout that is rechewed and swallowed or spit out. Seen in infants of severely disturbed mothers. Induce vomiting to seek attention. Resolving emotional trigger is best Rx.

42. Mouth: • Cyst on the floor of mouth – ranula (treat with excision) • Midline mass on floor of mouth – may be ectopic thyroid, shouldn’t be removed • Parotitis: most cases are idiopathic and don’t require Rx. (think mumps, HIV) • Mikulicz’ disease: parotid swelling, dry mouth and poor tear production • Ectodermal hypoplasia: X linked, underdeveloped or absent teeth, absence of sweat glands. Dx: skin bx  no sweat pores • Hallerman Streiff Syndrome: underdeveloped small teeth, bird nose. • Gardener’s syndrome: extra teeth and polyps in large and small intestines (premalignant). AD inheritance. Rx: surgical removal of polyps.

43. Esophagus: • Varices: liver disease causes portal HTN– bright red/bloody stools, hematemesis, tarry stools. • TEF: with upper esophageal pouch is most common type. Presents with coughing during feeds in neonatal period. Film will show feeding tube coiled in blind ending esophagus. Keep NPO, drain blind ending puch, surgery. Will describe copious secretions, “can’t pass NG”, polyhdramnios.

44. Question: • 15 y/o M p/w melena and anemia. EGD shows nodular gastritis of the antrum and an ulcer. Biopsies demonstrate spiral-shaped organisms c/w H. Pylori. You prescribe Amox, Clarithromycin, and Lansoprazole x 2 weeks. At f/u visit, family asks if Rx was successful. • Of the following, the PREFERRED NONIVASIVE test to evaluate whether the pathogen is eradicated is: • A. Fecal campylobacter-like organisms (CLO) • B. Fecal H. Pylori antigen • C. Salivary H. Pylori antibody • D. Serum H. Pylori immunoglobulin G serology • E. Serum H. Pylori urease concentrations

45. Answer: • A. Fecal campylobacter-like organisms (CLO) • B. Fecal H. Pylori antigen • C. Salivary H. Pylori antibody • D. Serum H. Pylori immunoglobulin G serology • E. Serum H. Pylori urease concentrations

46. Explanation: • H. Pylori is known risk factor for gastritis and duodenal ulcers. • Gold standard for dx is EGD with biopsy • Best non invasive test: H. Pylori fecal antigen • Urease breath test also good test • H. Pylori IgG is a useful marker of epidemiologic studies of past or current infection, but sensitivity and PPV in children is suboptimal. • + IgG screen should be confirmed with a second test. • Testing for eradication of organisms after treatment should be done 1 month after therapy completed.

47. Stomach: • PUD: vomiting after eating, epigastric pain severe enough to wake kid out of sleep, guaiac positive stools. EGD is best study with bx for H. Pylori. Rx: H2 blockers, Sucralfate (coats damaged mucosa), misoprostol (PG analogues, enhance bicarb production and decrease gastric acid production), PPI (inhibit gastric acid pump) • H. Pylori: Dx: H. pylori IgG only as screening tool, confirm with fecal antigen or Urea breath test, or bx. Triple therapy: PPI + 2 abx (Amox and Flagyl; Amox and Clarithro) x 14 days. • NSAID dyspepsia: cuase GI sx by interfering with PG synthesis. Rx: antacids and food. • Zollinger Ellison Syndrome: gastrin secreting tumor, present with sx of PUD. Dx: fasting gastrin levels.

48. Question: • A 16 y/o M comes to your office with a 6 month hx of abdominal cramping. States that the cramps immediately precede a BM and that passage of stool results in pain relief. No clear association with food. His BMs are variable, ranging from hard stools every other day to loose stools several times/day. Weight and height are normal, as is PE findings. Stool guaiac, CBC, ESR, LFTs, IgA, TTG are all normal. Stool studies negative for Giradia, C. Diff and enteric pathogens. • Of the following, the MOST appropriate next step is: • A. Colonoscopy and biopsy • B. Fiber supplementation • C. Observation • D. Oral tegaserod • E. Referral to psychiatrist.

49. Answer: • A. Colonoscopy and biopsy • B. Fiber supplementation • C. Observation • D. Oral tegaserod • E. Referral to psychiatrist.

50. Explanation: • IBS is a functional GI disorder that typically occurs in teens and young adults. • Defined as abdominal discomfort that is relieved with defecation and associated with either a change in frequency or consistency of stool. • Diarrhea is common, rectal bleeding is not. • Need to exclude infectious causes of diarrhea. • Thought to be due to altered colonic motility, alterations in colonic microflora and excess gas production. Psych factors can also worsen sx. • Treatment often begins with trial of fiber supplementation – helps up to 50%. • Tegaserod: effective for constipation predominant IBS (5HT4 agonist) – not first line and not indicated for pts with diarrhea. • If no red flags, endoscopic evaluation should be postponed until after trial of therapy.