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ABIM GI practice questions

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Question 1Esophagus and Stomach

A 58-year-old man reports 3 months of progressive solid-food dysphagia and 8 kg weight loss. He has smoked for 30 years. Which diagnosis must be excluded first?

  1. Diffuse esophageal spasm
  2. Esophageal adenocarcinoma Correct answer.
  3. Eosinophilic esophagitis
  4. Achalasia

Explanation

Progressive dysphagia to solids with weight loss and tobacco exposure in an older adult is a red-flag presentation that mandates exclusion of esophageal malignancy before assuming a benign motility or inflammatory disorder.

Question 2Esophagus and Stomach

Which finding on esophageal manometry defines achalasia?

  1. Premature contractions in the distal esophagus
  2. Hypertensive lower esophageal sphincter with normal peristalsis
  3. Absent peristalsis with failure of lower esophageal sphincter relaxation Correct answer.
  4. Normal peristalsis with hypotensive sphincter

Explanation

Achalasia is defined by aperistalsis together with incomplete relaxation of the lower esophageal sphincter on swallowing; elevated integrated relaxation pressure is the manometric hallmark.

Question 3Esophagus and Stomach

A 45-year-old woman has intermittent solid-food dysphagia and a history of food impaction. Biopsies show 25 eosinophils per high-power field. Which treatment is first-line for long-term control?

  1. Calcium channel blockers
  2. Endoscopic dilation alone
  3. Topical swallowed corticosteroids Correct answer.
  4. Proton pump inhibitor trial

Explanation

Swallowed topical corticosteroids are first-line pharmacologic therapy for eosinophilic esophagitis and induce remission of both symptoms and histology; dietary elimination is an alternative first-line approach.

Question 4Esophagus and Stomach

Which statement best characterizes the mechanism of proton pump inhibitors?

  1. Competitive antagonism at the histamine H2 receptor
  2. Irreversible inhibition of the H+/K+ ATPase on the parietal cell canalicular membrane Correct answer.
  3. Neutralization of gastric acid by a basic salt
  4. Blockade of the M3 muscarinic receptor

Explanation

PPIs are acid-activated prodrugs that covalently bind and irreversibly inhibit the parietal cell H+/K+ ATPase, suppressing the final common step of acid secretion.

Question 5Esophagus and Stomach

A 30-year-old man has heartburn, dysphagia, and Raynaud phenomenon with thickened skin on the fingers. Which esophageal motility finding is most likely?

  1. Low-amplitude peristalsis in the smooth muscle esophagus and hypotensive sphincter Correct answer.
  2. Normal peristalsis with premature contractions
  3. Nutcracker contractions
  4. Aperistalsis with elevated relaxation pressure

Explanation

Scleroderma (systemic sclerosis) causes smooth muscle atrophy of the distal esophagus, producing weak or absent distal peristalsis and an incompetent lower esophageal sphincter, which explains severe reflux.

Question 6Esophagus and Stomach

Which is the most common cause of acute upper gastrointestinal bleeding in hospitalized patients?

  1. Gastric and duodenal stress ulcers Correct answer.
  2. Mallory-Weiss tear
  3. Dieulafoy lesion
  4. Esophageal varices

Explanation

Stress-related mucosal disease, particularly gastric and duodenal stress ulcers, is the leading cause of upper GI bleeding in critically ill hospitalized patients, driven by splanchnic hypoperfusion.

Question 7Esophagus and Stomach

A 62-year-old man with osteoarthritis on chronic ibuprofen develops a 1.5 cm clean-based duodenal ulcer. What is the most appropriate next step?

  1. Stop NSAID and start a proton pump inhibitor Correct answer.
  2. Continue NSAID and add an H2 blocker
  3. Start misoprostol without stopping the NSAID
  4. Refer for immediate surgery

Explanation

NSAID-associated peptic ulcers are best managed by discontinuing the offending agent and providing acid suppression with a PPI to promote healing.

Question 8Esophagus and Stomach

A 50-year-old woman has dysphagia, a Schatzki ring found on endoscopy, and intermittent food impaction. Which management is most appropriate?

  1. Endoscopic bougie or balloon dilation Correct answer.
  2. Nissen fundoplication
  3. Long-term calcium channel blockers
  4. Esophagectomy

Explanation

Symptomatic Schatzki rings are treated with endoscopic dilation, which relieves dysphagia; acid suppression is often added to reduce recurrence.

Question 9Esophagus and Stomach

Which finding is most specific for Barrett esophagus on endoscopy?

  1. Erythema of the distal esophagus
  2. White plaques in the mid-esophagus
  3. Salmon-colored mucosa extending above the gastroesophageal junction with intestinal metaplasia on biopsy Correct answer.
  4. A smooth stricture at the squamocolumnar junction

Explanation

Barrett esophagus is diagnosed when columnar-appearing mucosa extends proximal to the gastroesophageal junction and biopsy confirms intestinal metaplasia with goblet cells.

Question 10Esophagus and Stomach

A 70-year-old man with long-segment Barrett esophagus and no dysplasia asks about surveillance. What is the recommended interval?

  1. Every 3 years Correct answer.
  2. Every 6 months
  3. Every 10 years
  4. No surveillance needed

Explanation

For nondysplastic Barrett esophagus, guidelines recommend endoscopic surveillance approximately every 3 years to detect progression to dysplasia or cancer.

Question 11Esophagus and Stomach

A 40-year-old woman has halitosis, regurgitation of undigested food, and a sense of fullness after meals. Barium swallow shows a dilated esophagus tapering at the GE junction. Which diagnosis is most consistent?

  1. Gastroesophageal reflux disease
  2. Esophageal cancer
  3. Diffuse esophageal spasm
  4. Achalasia Correct answer.

Explanation

A dilated esophagus with smooth tapering at the lower esophageal sphincter (bird-beak appearance) plus regurgitation of retained food and halitosis is classic for achalasia.

Question 12Esophagus and Stomach

Which is the most common cause of peptic ulcer disease in patients not taking NSAIDs?

  1. Crohn disease
  2. Cytomegalovirus infection
  3. Zollinger-Ellison syndrome
  4. Helicobacter pylori infection Correct answer.

Explanation

H. pylori infection and NSAID use account for the vast majority of peptic ulcers; in the absence of NSAIDs, H. pylori is the dominant cause.

Question 13Esophagus and Stomach

A 55-year-old man with a bleeding duodenal ulcer undergoes endoscopy. What is the preferred initial endoscopic therapy for a spurting vessel?

  1. Epinephrine injection alone
  2. Combination therapy with epinephrine injection plus a mechanical clip or thermal coagulation Correct answer.
  3. Nasogastric lavage
  4. Oral proton pump inhibitor only

Explanation

For actively bleeding ulcers, combination endoscopic therapy (epinephrine injection plus a second modality such as clips or thermal coagulation) reduces rebleeding compared with monotherapy.

Question 14Esophagus and Stomach

Which symptom pattern is most typical of a Zenker diverticulum?

  1. Progressive solid dysphagia with weight loss
  2. Heartburn relieved by antacids
  3. Regurgitation of undigested food and halitosis with dysphagia Correct answer.
  4. Odynophagia with oral thrush

Explanation

Zenker diverticulum arises in Killian triangle and causes retention of food in the pouch, producing regurgitation of undigested food, halitosis, and dysphagia.

Question 15Esophagus and Stomach

A patient with known cirrhosis presents with hematemesis. Which medication should be started early to reduce bleeding from esophageal varices?

  1. Omeprazole
  2. Erythromycin
  3. Octreotide Correct answer.
  4. Metoclopramide

Explanation

Somatostatin analogues such as octreotide reduce splanchnic blood flow and portal pressure and should be initiated early in suspected variceal hemorrhage.

Question 16Esophagus and Stomach

Which of the following is the strongest risk factor for gastric adenocarcinoma?

  1. Celiac disease
  2. Barrett esophagus
  3. Helicobacter pylori infection Correct answer.
  4. Adenomatous colon polyps

Explanation

Chronic H. pylori infection is the most important established risk factor for noncardia gastric adenocarcinoma, largely through chronic gastritis and atrophic changes.

Question 17Esophagus and Stomach

A 35-year-old woman has recurrent peptic ulcers, diarrhea, and a markedly elevated fasting gastrin. Which test best confirms Zollinger-Ellison syndrome?

  1. Serum gastrin after a secretin stimulation showing a paradoxical rise Correct answer.
  2. Random serum gastrin alone
  3. Serum chromogranin A
  4. Fecal calprotectin

Explanation

A paradoxical increase in serum gastrin after secretin administration supports gastrinoma; it distinguishes Zollinger-Ellison syndrome from other causes of hypergastrinemia.

Question 18Esophagus and Stomach

Which mechanism explains why PPIs are best given 30 to 60 minutes before a meal?

  1. Meals reduce hepatic first-pass metabolism
  2. Acid secretion stimulated by the meal activates the prodrug at the canalicular membrane Correct answer.
  3. Food increases renal clearance of the drug
  4. The drug binds dietary protein

Explanation

PPIs are acid-labile prodrugs that require activation in the acidic secretory canaliculus; dosing before a meal aligns peak drug levels with meal-stimulated proton pump activity for maximal suppression.

Question 19Esophagus and Stomach

A 28-year-old man has acute onset of severe retrosternal chest pain after forceful vomiting; endoscopy shows a longitudinal mucosal tear at the GE junction. What is the diagnosis?

  1. Mallory-Weiss tear Correct answer.
  2. Boerhaave syndrome
  3. Eosinophilic esophagitis
  4. Esophageal varices

Explanation

A Mallory-Weiss tear is a partial-thickness mucosal laceration at the gastroesophageal junction caused by retching, often presenting with hematemesis.

Question 20Esophagus and Stomach

Which endoscopic finding suggests a benign gastric ulcer rather than malignancy?

  1. Smooth, regular margins with radiating folds Correct answer.
  2. A large ulcer with a necrotic base
  3. Irregular heaped margins with nodularity
  4. An ulcer in the fundus with distorted anatomy

Explanation

Benign gastric ulcers typically have smooth, regular margins and radiating folds; malignant ulcers often have irregular, heaped, or nodular edges.

Question 21Esophagus and Stomach

Which is the recommended first-line eradication regimen for H. pylori in most regions with low clarithromycin resistance?

  1. Clarithromycin monotherapy for 10 days
  2. Amoxicillin alone for 7 days
  3. Bismuth subsalicylate alone for 14 days
  4. Proton pump inhibitor, amoxicillin, and clarithromycin for 14 days Correct answer.

Explanation

Standard triple therapy with a PPI plus amoxicillin and clarithromycin for 14 days is first-line where clarithromycin resistance is low; bismuth quadruple therapy is preferred in high-resistance areas.

Question 22Esophagus and Stomach

A patient has a gastric ulcer and is found to have a gastric outlet obstruction. Which feature on presentation is most characteristic?

  1. Dysphagia to solids only
  2. Hematochezia with normal electrolytes
  3. Copious nonbilious emesis with hypochloremic hypokalemic metabolic alkalosis Correct answer.
  4. Bilious emesis with metabolic acidosis

Explanation

Gastric outlet obstruction causes retention of gastric contents with vomiting of nonbilious material, leading to loss of hydrogen and chloride and a hypochloremic, hypokalemic metabolic alkalosis.

Question 23Esophagus and Stomach

Which statement about the gastroesophageal junction barrier is correct?

  1. The lower esophageal sphincter is skeletal muscle
  2. Salivary bicarbonate has no role in esophageal clearance
  3. The crural diaphragm contributes to the antireflux barrier Correct answer.
  4. Transient LES relaxations are the main mechanism of reflux in healthy people

Explanation

The antireflux barrier includes the intrinsic smooth-muscle LES and the extrinsic crural diaphragm; both contribute to preventing reflux.

Question 24Esophagus and Stomach

A 60-year-old woman has iron deficiency anemia and is found to have atrophic gastritis with autoantibodies to parietal cells. Which complication is she at risk for?

  1. Zinc deficiency with acrodermatitis
  2. Vitamin B12 deficiency with megaloblastic anemia Correct answer.
  3. Vitamin C deficiency with scurvy
  4. Essential fatty acid deficiency

Explanation

Autoimmune atrophic gastritis destroys parietal cells, causing loss of intrinsic factor and subsequent vitamin B12 malabsorption, leading to pernicious anemia.

Question 25Esophagus and Stomach

A patient with achalasia is treated with pneumatic dilation. Which complication should be monitored for immediately afterward?

  1. Gastric outlet obstruction
  2. Esophageal perforation Correct answer.
  3. Bile reflux gastritis
  4. Hypergastrinemia

Explanation

Pneumatic dilation forcibly tears the LES and carries a risk of esophageal perforation, which presents with severe chest pain, fever, and mediastinal air.

Question 26Esophagus and Stomach

A 58-year-old man reports weekly heartburn and regurgitation that partially improve with lifestyle changes. He has no dysphagia, weight loss, or anemia. Which medication is most appropriate for initial pharmacologic therapy?

  1. Liquid sucralfate taken after each meal
  2. On-demand antacid at the time of symptoms
  3. Bedtime histamine-2 receptor antagonist
  4. Once-daily proton pump inhibitor taken before breakfast Correct answer.

Explanation

For typical GERD without alarm features, a once-daily proton pump inhibitor taken 30 to 60 minutes before the first meal is the most effective initial acid-suppressive strategy. Healing and symptom relief are superior to on-demand antacids or H2 blockers in this setting.

Question 27Esophagus and Stomach

A 45-year-old woman has a 9 cm, smooth, well-demarcated gastric submucosal mass found incidentally. Endoscopic ultrasound shows a hypoechoic lesion arising from the fourth (muscular) layer, and biopsy with immunohistochemistry is positive for CD117 (KIT). Which is the most likely diagnosis?

  1. Gastric schwannoma
  2. Leiomyoma
  3. Gastric carcinoid tumor
  4. Gastrointestinal stromal tumor Correct answer.

Explanation

Gastrointestinal stromal tumors arise from the interstitial cells of Cajal and characteristically express KIT (CD117). They most often originate from the muscularis propria, producing a submucosal-appearing mass.

Question 28Esophagus and Stomach

A 66-year-old man with cirrhosis and known esophageal varices presents with hematemesis. Which pharmacologic agent should be given early to reduce ongoing variceal bleeding?

  1. Intravenous octreotide Correct answer.
  2. Intravenous vitamin K
  3. Oral propranolol
  4. Oral sucralfate

Explanation

Somatostatin analogues such as octreotide cause splanchnic vasoconstriction and reduce portal pressure, and are recommended as soon as acute variceal hemorrhage is suspected. Non-selective beta blockers are used for prophylaxis, not acute bleeding.

Question 29Esophagus and Stomach

A 52-year-old woman has progressive solid-food dysphagia, regurgitation of undigested food, and a barium swallow showing a dilated esophagus with a smooth tapering distal segment. Manometry shows absent peristalsis with failure of lower esophageal sphincter relaxation. Which finding on high-resolution manometry best distinguishes type I from type II achalasia?

  1. Presence of panesophageal pressurization with swallows Correct answer.
  2. Absence of lower esophageal sphincter relaxation
  3. Elevated integrated relaxation pressure
  4. Absent distal esophageal peristalsis

Explanation

The Chicago classification distinguishes achalasia subtypes by pressurization patterns: type II shows panesophageal pressurization in at least 20% of swallows, whereas type I lacks pressurization. Both subtypes share absent peristalsis and impaired esophagogastric junction relaxation.

Question 30Esophagus and Stomach

A 38-year-old man has burning epigastric pain relieved by meals and at night, and endoscopy shows a 1 cm ulcer in the gastric antrum. Biopsy is negative for malignancy. He is not taking NSAIDs and has no alarm features. Which single test is most appropriate to establish the cause of this ulcer?

  1. Serum gastrin level
  2. Urea breath test for H. pylori Correct answer.
  3. Fecal occult blood test
  4. 24-hour esophageal pH monitoring

Explanation

H. pylori is the most common cause of gastric ulcers in patients not taking NSAIDs, so documenting infection with a urea breath test, stool antigen, or histology is the key step. Identifying and eradicating infection reduces recurrence and guides management.

Question 31Small Intestine, Colon, and Anorectum

A 28-year-old presents with chronic diarrhea, weight loss, and iron-deficiency anemia. Duodenal biopsy shows villous blunting and increased intraepithelial lymphocytes. Which serologic test is most appropriate for initial screening?

  1. Anti-gliadin IgG antibodies
  2. Serum chromogranin A
  3. Anti-saccharomyces cerevisiae antibodies
  4. Tissue transglutaminase IgA with total IgA level Correct answer.

Explanation

Celiac disease screening uses IgA tissue transglutaminase, and total IgA must be checked because IgA deficiency can cause false-negative results. Anti-gliadin testing is no longer recommended for screening because of low specificity.

Question 32Small Intestine, Colon, and Anorectum

Which finding on duodenal histology is characteristic of celiac disease?

  1. Villous hypertrophy with goblet cell hyperplasia
  2. Submucosal noncaseating granulomas
  3. Villous blunting with increased intraepithelial lymphocytes Correct answer.
  4. Crypt abscesses with neutrophilic infiltration

Explanation

Celiac disease produces villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes. The other findings reflect different processes such as infection, granulomatous disease, or acute inflammation.

Question 33Small Intestine, Colon, and Anorectum

A patient with known celiac disease on a gluten-free diet develops recurrent diarrhea. Which condition should be suspected if symptoms persist despite documented adherence?

  1. Irritable bowel syndrome
  2. Refractory celiac disease Correct answer.
  3. Lactose intolerance
  4. Microscopic colitis

Explanation

Persistent symptoms despite a strict gluten-free diet raise concern for refractory celiac disease, which requires further evaluation including repeat biopsy. The other conditions can cause diarrhea but do not specifically represent failure to respond to gluten withdrawal.

Question 34Small Intestine, Colon, and Anorectum

Which organism most commonly causes traveler's diarrhea?

  1. Clostridioides difficile
  2. Giardia lamblia
  3. Entamoeba histolytica
  4. Enterotoxigenic Escherichia coli Correct answer.

Explanation

Enterotoxigenic E. coli is the leading cause of traveler's diarrhea worldwide. The other organisms cause diarrhea but are less common causes in travelers.

Question 35Small Intestine, Colon, and Anorectum

A patient develops watery diarrhea after a course of broad-spectrum antibiotics. Which test is most appropriate to confirm the suspected diagnosis?

  1. Duodenal aspirate for Giardia
  2. Stool culture for Salmonella
  3. Stool testing for Clostridioides difficile toxin or PCR Correct answer.
  4. Serum anti-transglutaminase IgA

Explanation

Antibiotic-associated diarrhea raises concern for C. difficile infection, confirmed with stool toxin testing or nucleic acid amplification. The other tests address different causes and are not first-line for this presentation.

Question 36Small Intestine, Colon, and Anorectum

Which finding is most suggestive of small intestinal bacterial overgrowth (SIBO)?

  1. Positive anti-saccharomyces cerevisiae antibody
  2. Elevated fasting serum gastrin
  3. Positive hydrogen breath test after glucose ingestion Correct answer.
  4. Elevated fecal calprotectin

Explanation

SIBO is often assessed with a hydrogen breath test, which detects early hydrogen production from bacterial fermentation of a carbohydrate load. The other tests evaluate different conditions such as gastrinoma, inflammation, or Crohn disease.

Question 37Small Intestine, Colon, and Anorectum

A patient with cirrhosis and ascites presents with diarrhea and is found to have SIBO. Which factor most predisposes to SIBO in this setting?

  1. Impaired intestinal motility Correct answer.
  2. Rapid colonic transit
  3. Bile acid excess
  4. Increased gastric acid secretion

Explanation

Impaired intestinal motility allows stasis and bacterial proliferation in the small bowel, a key mechanism of SIBO. Cirrhosis and other systemic illness can slow motility.

Question 38Small Intestine, Colon, and Anorectum

Which test is considered the reference standard for diagnosing short bowel syndrome severity?

  1. Serum citrulline level
  2. Measurement of remaining small bowel length and anatomy Correct answer.
  3. D-xylose absorption test
  4. Fecal fat quantification

Explanation

Short bowel syndrome is defined anatomically by the length and segment of remaining small intestine, which predicts absorptive capacity. Serum citrulline can support assessment but does not define the anatomy.

Question 39Small Intestine, Colon, and Anorectum

A patient with short bowel syndrome and a jejunostomy has high stoma output. Which dietary strategy is most appropriate?

  1. Large bolus meals with free water
  2. High simple sugar intake
  3. Small frequent meals with oral rehydration solution Correct answer.
  4. High-fat, low-carbohydrate diet

Explanation

Small frequent meals and oral rehydration solution with appropriate sodium and glucose optimize absorption and reduce osmotic losses in short bowel syndrome. Large boluses and free water worsen output.

Question 40Small Intestine, Colon, and Anorectum

Which finding is most consistent with a diagnosis of irritable bowel syndrome with diarrhea (IBS-D)?

  1. Iron-deficiency anemia
  2. Recurrent abdominal pain related to defecation with altered stool form Correct answer.
  3. Nocturnal diarrhea with weight loss
  4. Fecal calprotectin greater than 500 mcg/g

Explanation

IBS is defined by recurrent abdominal pain associated with defecation and change in stool form or frequency, without alarm features. Alarm features such as weight loss, anemia, or markedly elevated calprotectin suggest organic disease.

Question 41Small Intestine, Colon, and Anorectum

Which medication class is first-line for global symptom relief in IBS-D?

  1. Tricyclic antidepressants Correct answer.
  2. Rifaximin
  3. Loperamide
  4. Lubiprostone

Explanation

Tricyclic antidepressants, particularly at low doses, are first-line for global IBS symptoms including pain because of their neuromodulatory and anticholinergic effects. Other agents target specific symptoms or require selection based on predominant bowel habit.

Question 42Small Intestine, Colon, and Anorectum

A 60-year-old presents with bloody diarrhea and abdominal pain. Colonoscopy shows continuous inflammation extending from the rectum. Which diagnosis is most likely?

  1. Ischemic colitis
  2. Crohn disease
  3. Microscopic colitis
  4. Ulcerative colitis Correct answer.

Explanation

Ulcerative colitis characteristically involves the rectum and extends proximally in a continuous fashion. Crohn disease tends to be patchy with skip lesions.

Question 43Small Intestine, Colon, and Anorectum

Which feature most favors Crohn disease over ulcerative colitis?

  1. Continuous mucosal involvement from the rectum
  2. Pseudopolyps
  3. Transmural inflammation with fistulae Correct answer.
  4. Crypt abscesses

Explanation

Crohn disease is transmural and can produce fistulae, strictures, and skip lesions. Ulcerative colitis is confined to the mucosa and is continuous from the rectum.

Question 44Small Intestine, Colon, and Anorectum

A patient with ulcerative colitis is being considered for biologic therapy. Which infection screening is required before starting anti-TNF therapy?

  1. Latent tuberculosis screening Correct answer.
  2. Hepatitis C RNA
  3. HIV viral load
  4. Helicobacter pylori stool antigen

Explanation

Anti-TNF agents increase the risk of reactivation of latent tuberculosis, so screening is mandatory before initiation. Other infections may be relevant but latent TB screening is a specific requirement.

Question 45Small Intestine, Colon, and Anorectum

Which finding on colonoscopy is most consistent with ischemic colitis?

  1. Deep ulceration with fistulae
  2. Continuous inflammation from the rectum
  3. Multiple pseudopolyps
  4. Segmental mucosal edema and erythema in a watershed distribution Correct answer.

Explanation

Ischemic colitis typically produces segmental injury in watershed areas such as the splenic flexure or rectosigmoid junction, with mucosal edema and erythema. Rectal sparing is common.

Question 46Small Intestine, Colon, and Anorectum

Which is the most common cause of acute mesenteric ischemia?

  1. Nonocclusive mesenteric ischemia
  2. Arterial embolism Correct answer.
  3. Venous thrombosis
  4. Vasculitis

Explanation

Arterial embolism, often from a cardiac source, is the most common cause of acute mesenteric ischemia. Venous thrombosis and nonocclusive ischemia are less common.

Question 47Small Intestine, Colon, and Anorectum

A patient with atrial fibrillation develops severe abdominal pain out of proportion to examination findings. Which initial imaging study is most appropriate?

  1. Abdominal plain radiograph
  2. CT angiography of the abdomen Correct answer.
  3. Barium enema
  4. Colonoscopy

Explanation

CT angiography is the preferred initial imaging study for suspected acute mesenteric ischemia because it identifies arterial occlusion and assesses bowel viability. Plain films are nonspecific and may be normal early.

Question 48Small Intestine, Colon, and Anorectum

Which finding on abdominal imaging is most suggestive of colonic obstruction?

  1. Pneumatosis intestinalis
  2. Portal venous gas
  3. Thickened gallbladder wall
  4. Dilated bowel loops with air-fluid levels Correct answer.

Explanation

Dilated bowel loops with air-fluid levels indicate obstruction with proximal accumulation of fluid and gas. Pneumatosis and portal venous gas suggest ischemia or necrosis rather than simple obstruction.

Question 49Small Intestine, Colon, and Anorectum

Which is the most appropriate initial management for a patient with a large bowel obstruction and signs of peritonitis?

  1. Emergent surgical consultation Correct answer.
  2. Observation with serial examinations
  3. Colonoscopy with decompression
  4. Oral laxatives

Explanation

Peritonitis with large bowel obstruction suggests perforation or ischemia and requires emergent surgical evaluation. Nonoperative measures are inappropriate in this setting.

Question 50Small Intestine, Colon, and Anorectum

Which is the most common cause of acute colonic pseudo-obstruction (Ogilvie syndrome)?

  1. Inflammatory bowel disease
  2. Diverticulitis
  3. Colorectal cancer
  4. Severe systemic illness or surgery Correct answer.

Explanation

Ogilvie syndrome typically occurs in hospitalized patients with severe systemic illness, surgery, or metabolic derangements. Mechanical obstruction must be excluded first.