Irritable bowel syndrome UK Medical PG Practice Questions and MCQs
Practice UK Medical PG questions for Irritable bowel syndrome. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Irritable bowel syndrome UK Medical PG Question 1: A 44-year-old woman presents with recurrent episodes of severe right upper quadrant pain after eating fatty foods. The pain radiates to her right shoulder and lasts several hours. What is the most likely diagnosis?
- A. Peptic ulcer disease
- B. Acute pancreatitis
- C. Biliary colic (Correct Answer)
- D. Gastroenteritis
- E. Appendicitis
Irritable bowel syndrome Explanation: ***Biliary colic***- This presentation of episodic, severe **right upper quadrant (RUQ) pain** lasting several hours and radiating to the **right shoulder** is the classic description of biliary colic caused by temporary obstruction of the cystic duct by a gallstone.- The pain is typically precipitated by **fatty meals** because cholecystokinin release causes the gallbladder to contract forcefully against the obstructing stone.*Peptic ulcer disease*- Pain associated with **peptic ulcer disease (PUD)** is usually epigastric, gnawing, or burning, and does not typically radiate to the right shoulder in this manner.- PUD pain is often related to the timing of meals but is usually relieved by antacids, unlike the intense, sustained colic seen here.*Acute pancreatitis*- **Acute pancreatitis** pain is typically constant, severe, and boring, radiating straight through to the **back**, not primarily to the right shoulder.- It is associated with systemic signs and significantly elevated serum **amylase** and **lipase** levels, which distinguish it from simpler biliary colic.*Gastroenteritis*- **Gastroenteritis** usually causes more diffuse, crampy abdominal pain, accompanied by prominent symptoms like vomiting and **diarrhea**.- It does not present as localized, recurrent, severe RUQ pain lasting hours, nor is it specifically triggered by **fatty food intake**.*Appendicitis*- **Appendicitis** pain classically starts periumbilical before localizing to the **right lower quadrant (RLQ)** (McBurney's point).- The pain is usually constant, progressive over 24-48 hours, and associated with signs of peritoneal irritation, unlike the episodic nature described here.
Irritable bowel syndrome UK Medical PG Question 2: A 38-year-old woman presents with recurrent episodes of severe abdominal pain and psychiatric symptoms. Her urine turns dark during attacks. Family history reveals similar episodes. What is the inheritance pattern?
- A. Autosomal recessive
- B. Autosomal dominant (Correct Answer)
- C. X-linked recessive
- D. X-linked dominant
- E. Mitochondrial
Irritable bowel syndrome Explanation: ***Autosomal dominant***
- The clinical picture of recurrent severe abdominal pain, psychiatric symptoms, and dark urine during attacks is highly suggestive of **Acute Intermittent Porphyria (AIP)**.
- AIP is caused by a deficiency in **hydroxymethylbilane synthase (PBG deaminase)** and is inherited in an **autosomal dominant** fashion, which explains the positive family history.
*Autosomal recessive*
- **Autosomal recessive** disorders typically manifest if two copies of the defective gene are inherited, often presenting in siblings but not consistently across multiple generations (vertical transmission) as implied by the family history.
- Conditions like **Congenital erythropoietic porphyria** are autosomal recessive but primarily cause photosensitivity and hemolytic anemia, not neurovisceral crises.
*X-linked recessive*
- **X-linked recessive** disorders predominantly affect males and are transmitted from carrier mothers to sons, a pattern inconsistent with a female patient with similar episodes in the family.
- Common examples like **Hemophilia** or **Duchenne Muscular Dystrophy** have sex-linked inheritance patterns that do not match the presented symptoms or inheritance.
*X-linked dominant*
- **X-linked dominant** inheritance would show affected fathers passing the trait to all daughters but none of their sons, and affected mothers passing it to half of their children, which is not the typical pattern for AIP.
- **X-linked protoporphyria**, a rare porphyria, follows this pattern but presents primarily with severe photosensitivity and hepatobiliary complications, not the neurovisceral attacks seen here.
*Mitochondrial*
- **Mitochondrial inheritance** is characterized by exclusive **maternal transmission**, meaning all children of an affected mother are affected, but no children of an affected father. This pattern differs from the general family history for AIP.
- Mitochondrial disorders primarily affect high-energy-demand organs, and while they can have neurological components, most porphyrias are nuclear-encoded genetic disorders, making mitochondrial inheritance highly unlikely.
Irritable bowel syndrome UK Medical PG Question 3: A 47-year-old man presents with acute severe abdominal pain and vomiting. He has a family history of similar episodes. Serum amylase is normal but urinary porphobilinogen is elevated. What triggers should be avoided?
- A. Fasting
- B. Alcohol
- C. Barbiturates
- D. Stress
- E. All of the above (Correct Answer)
Irritable bowel syndrome Explanation: ***All of the above***- The patient's presentation with acute severe abdominal pain, vomiting, family history of similar episodes, normal serum amylase, and elevated **urinary porphobilinogen** strongly points to an **Acute Intermittent Porphyria (AIP)** attack.- Attacks are triggered by factors that induce **hepatic ALA synthase (ALAS1)**, including specific drugs (e.g., **barbiturates**), metabolic stress (e.g., **fasting**, **alcohol**), and physiological factors (e.g., **stress**), all of which decrease regulatory heme. *Fasting*- **Fasting** or significant caloric restriction is a major trigger because the resulting carbohydrate deficiency reduces heme synthesis.- This leads to de-repression of **hepatic ALA synthase (ALAS1)**, increasing the production of neurotoxic porphyrin precursors.*Alcohol*- **Alcohol** metabolism induces **cytochrome P450 enzymes**, consuming available hepatic heme.- This consumption reduces the feedback inhibition on **ALAS1**, leading to an increase in porphyrin precursors.*Barbiturates*- **Barbiturates** are well-known inducers of the **hepatic cytochrome P450 system**.- This induction rapidly depletes the hepatic heme pool, lifting the natural feedback inhibition on **ALAS1** and causing accumulation of toxic precursors like **ALA** and **PBG**.*Stress*- Both emotional and physical **stress**, as well as infections, are recognized non-pharmacological precipitants of acute porphyria attacks.- Stress-induced attacks are likely mediated by associated hormonal shifts and metabolic imbalances that disrupt the heme synthesis pathway.
Irritable bowel syndrome UK Medical PG Question 4: A 51-year-old woman presents with progressive dysphagia and weight loss. She has a history of Barrett's esophagus on surveillance. Upper endoscopy shows a stricturing lesion. What is the most appropriate next step?
- A. Barium swallow
- B. Multiple biopsies of the lesion (Correct Answer)
- C. CT chest and abdomen
- D. Endoscopic ultrasound
- E. PET scan
Irritable bowel syndrome Explanation: ***Multiple biopsies of the lesion***- Given the history of **Barrett's esophagus** and progressive symptoms (**dysphagia**, **weight loss**), the stricturing lesion is highly suspicious for **esophageal adenocarcinoma**.- Obtaining **multiple tissue samples** is the definitive and most crucial first step to confirm the diagnosis, determine the histology, and guide all subsequent staging and treatment decisions.*Barium swallow*- While useful for evaluating the extent and geometry of the stricture, it is a **radiological technique** that cannot provide definitive **tissue diagnosis** (histology).- Utilizing a barium swallow as the next step would unnecessarily delay the required pathological confirmation of suspected **malignancy**.*CT chest and abdomen*- This is a crucial modality used for **staging** the disease (checking for distant metastases and large lymph nodes), which is performed *after* the cancer diagnosis is pathologically confirmed.- The information provided by the CT scan is necessary for determining the overall **stage** (M-stage) and defining the appropriate treatment strategy.*Endoscopic ultrasound*- EUS is critical for highly accurate local staging, specifically determining the depth of tumor invasion (**T stage**) and the status of regional lymph nodes (**N stage**).- Like the CT scan, EUS is a **staging tool** and follows the confirmed diagnosis provided by the initial biopsies.*PET scan*- The **PET scan** is useful for assessing metabolically active tumors and is used in staging to look for subtle or distant foci of metastases which may be missed on conventional CT.- This expensive and advanced imaging technique is reserved for **advanced staging** scenarios, typically after the diagnosis is confirmed and initial staging is underway.
Irritable bowel syndrome UK Medical PG Question 5: A 49-year-old man presents with acute severe epigastric pain radiating to his back. Serum amylase is 1500 U/L. CT shows pancreatic necrosis involving 40% of the gland. What is the most appropriate initial management?
- A. Immediate surgical necrosectomy
- B. Conservative management with IV fluids (Correct Answer)
- C. Endoscopic necrosectomy
- D. Percutaneous drainage
- E. Total pancreatectomy
Irritable bowel syndrome Explanation: ***Conservative management with IV fluids***- The initial management of severe acute pancreatitis, even when associated with **pancreatic necrosis**, is focused on **aggressive supportive care**, which primarily includes crystalloid administration for circulatory support, pain control, and monitoring.- Deferred intervention is the standard approach for **sterile pancreatic necrosis** because early surgical or endoscopic necrosectomy increases morbidity and mortality; intervention is typically reserved for confirmed **infected necrosis** occurring weeks later.*Immediate surgical necrosectomy*- Early surgical necrosectomy is associated with a significantly **higher mortality rate** and is generally contraindicated in the first 2-3 weeks, especially when the necrosis is sterile.- Surgical intervention is reserved for specific late complications, primarily **infected pancreatic necrosis** that fails conservative management, or uncontrolled bleeding.*Endoscopic necrosectomy*- Endoscopic approaches are minimally invasive alternatives to surgery for debridement but are generally performed only after the necrosis has successfully encapsulated into **walled-off necrosis (WON)**, typically 4 weeks or later.- Performing early debridement, endoscopic or surgical, is dangerous as the necrotic tissue is soft and poorly demarcated.*Percutaneous drainage*- This procedure is usually utilized for specific purposes, such as draining large, symptomatic acute fluid collections or for providing immediate control of suspected or proven **infected fluid collections** (abscesses) or infected necrosis.- It is not the cornerstone of initial volume resuscitation and systemic management for acute severe pancreatitis.*Total pancreatectomy*- This highly invasive technique carries massive morbidity (resulting in immediate **brittle diabetes** and exocrine insufficiency) and is reserved for extreme, life-threatening scenarios, such as widespread, uncontrolled pancreatic infection or massive hemorrhage.- It is never considered the appropriate initial step for managing acute pancreatitis.
Irritable bowel syndrome UK Medical PG Question 6: A 43-year-old woman presents with episodes of flushing, diarrhea, and bronchospasm. CT shows liver metastases and a small bowel mass. 24-hour urine 5-HIAA is markedly elevated. What is the primary tumor location?
- A. Appendix
- B. Small bowel (Correct Answer)
- C. Pancreas
- D. Lung
- E. Ovary
Irritable bowel syndrome Explanation: ***Small bowel*** - The constellation of **flushing**, **diarrhea**, and **bronchospasm** strongly indicates **carcinoid syndrome**, which, in the presence of **liver metastases**, is most commonly caused by **midgut carcinoid tumors**, particularly those arising from the **distal ileum**. - **Liver metastases** are crucial as they allow **serotonin** and other vasoactive substances to bypass hepatic metabolism, leading to systemic symptoms and elevated urinary **5-HIAA**. *Appendix* - While the **appendix** is the most common site for gastrointestinal carcinoid tumors, they are typically small, benign, and rarely metastasize or cause the full-blown **carcinoid syndrome**. - Appendiceal carcinoids are usually found incidentally and only cause symptoms if they obstruct the lumen. *Pancreas* - Pancreatic neuroendocrine tumors (PNETs) are known to secrete various hormones, but they typically cause syndromes related to hormones like **insulin** (insulinoma) or **gastrin** (gastrinoma), rather than classic carcinoid syndrome with prominent flushing and diarrhea. - Although a pancreatic primary could theoretically cause carcinoid syndrome, the clear presence of a **small bowel mass** on CT makes a small bowel primary significantly more likely. *Lung* - **Bronchial carcinoids** can indeed cause carcinoid syndrome, sometimes presenting with more atypical or prolonged flushing. - However, the patient's CT scan explicitly reveals a **small bowel mass** as the likely primary, making a lung primary less probable in this specific scenario. *Ovary* - Primary ovarian carcinoids are rare tumors that can cause carcinoid syndrome because their venous drainage directly enters the systemic circulation, bypassing the liver. - Yet, the identification of a **small bowel mass** on CT strongly points to a gastrointestinal primary tumor rather than an ovarian origin.
Irritable bowel syndrome UK Medical PG Question 7: A 59-year-old man presents with painless jaundice and weight loss. CT shows a mass in the pancreatic head. ERCP shows stricturing of the common bile duct. What is the most likely diagnosis?
- A. Chronic pancreatitis
- B. Pancreatic adenocarcinoma (Correct Answer)
- C. Cholangiocarcinoma
- D. Ampullary carcinoma
- E. Gallstone disease
Irritable bowel syndrome Explanation: ***Pancreatic adenocarcinoma***- The combination of **painless jaundice** and significant, unexplained **weight loss** in an older patient strongly suggests a periampullary malignancy.- The CT finding of a mass specifically located in the **pancreatic head** causing stricturing of the common bile duct confirms this as the most likely diagnosis, as the head is the most common site for this cancer.*Chronic pancreatitis*- Chronic pancreatitis typically presents with chronic or recurrent **severe epigastric pain** episodes; the history here emphasizes painless jaundice.- While it can cause strictures, the marked **weight loss** and the presence of a distinct mass on CT are more indicative of a malignant process than benign inflammation.*Cholangiocarcinoma*- Cholangiocarcinoma (bile duct cancer) causes obstructive jaundice, but the mass typically arises from the **biliary epithelium** itself, not the pancreatic parenchyma.- The tumor location is specified as a mass *in the pancreatic head*, making primary pancreatic cancer more probable than a distal cholangiocarcinoma.*Ampullary carcinoma*- While ampullary carcinomas also cause periampullary obstruction, they often lead to **fluctuating or intermittent jaundice** due to tumor sloughing.- They are also often associated with early symptoms like occult or frank **GI bleeding** and anemia, which are not key features here.*Gallstone disease*- Uncomplicated gallstone disease (choledocholithiasis) causing jaundice is usually painful (**biliary colic** or symptoms of cholangitis), contrasting with the **painless** history.- Gallstones do not typically cause a large, solid **mass** observed in the pancreatic head associated with rapid weight loss.
Irritable bowel syndrome UK Medical PG Question 8: A 54-year-old man presents with progressive dysphagia to solids over 3 months. He has a 40-year history of heartburn. Upper endoscopy shows a stricturing lesion at the GE junction. What is the most likely diagnosis?
- A. Benign peptic stricture
- B. Esophageal adenocarcinoma (Correct Answer)
- C. Achalasia
- D. Eosinophilic esophagitis
- E. Esophageal web
Irritable bowel syndrome Explanation: ***Esophageal adenocarcinoma***- The combination of a **long-standing history of GERD** (heartburn for 40 years) and the finding of a **stricturing lesion at the GE junction** is highly consistent with esophageal adenocarcinoma arising from **Barrett's esophagus**.- The presentation of **progressive dysphagia primarily to solids** over a short period (3 months) is the classic warning sign for malignancy causing luminal obstruction.*Benign peptic stricture*- While caused by chronic GERD, benign peptic strictures usually develop significantly **more slowly** (over years) and often cause symmetric, smooth narrowing.- Unlike cancer, benign strictures typically present with dysphagia that may improve with **proton pump inhibitor (PPI) therapy**, and they lack the invasive, irregular appearance of a malignant stricture on endoscopy.*Achalasia*- Achalasia is a motility disorder characterized by the failure of the **lower esophageal sphincter (LES) to relax**, typically causing progressive dysphagia to **both solids and liquids** simultaneously.- Endoscopy in achalasia usually shows a dilated esophagus with retained food, often with a "bird-beak" appearance on barium swallow, not a focal stricturing mass at the GE junction.*Eosinophilic esophagitis*- This condition is usually associated with **atopy** and presents with intermittent dysphagia, often leading to **food impaction**, typically in younger patients.- Endoscopic findings include characteristic **esophageal rings (trachea-like appearance)**, linear furrows, or white exudates, and the diagnosis relies on the presence of high numbers of eosinophils on biopsy.*Esophageal web*- Esophageal webs are thin, shelf-like mucosal membranes commonly found in the **proximal or mid esophagus**, often causing only intermittent, non-progressive dysphagia.- They are not associated with long-standing GERD/Barrett's esophagus, nor do they typically present as a thick, stricturing lesion found at the **GE junction**.
Irritable bowel syndrome UK Medical PG Question 9: A 52-year-old man presents with progressive jaundice and weight loss. MRCP shows stricturing of the common bile duct with upstream dilatation. CA 19-9 is markedly elevated. What is the most likely diagnosis?
- A. Choledocholithiasis
- B. Cholangiocarcinoma (Correct Answer)
- C. Pancreatic adenocarcinoma
- D. Primary sclerosing cholangitis
- E. Chronic pancreatitis
Irritable bowel syndrome Explanation: ***Cholangiocarcinoma***- This presentation of progressive **obstructive jaundice**, **weight loss**, and a solitary stricture on MRCP is highly characteristic of **cholangiocarcinoma**.- The markedly elevated **CA 19-9** is a standard tumor marker supporting the diagnosis of this biliary tract malignancy.*Choledocholithiasis*- Typically causes abrupt or **intermittent obstructive symptoms** (jaundice, cholangitis), often preceded by biliary colic.- MRCP would characteristically show **filling defects (stones)** within the duct, not primarily a **dominant intrinsic stricture**.*Pancreatic adenocarcinoma*- While it causes obstructive jaundice and weight loss with high CA 19-9, it usually compresses the **distal CBD** and often shows a **double duct sign** (dilated CBD and pancreatic duct).- The patient’s presentation focuses on a generic common bile duct stricture, which is more specific to biliary wall cancer (cholangiocarcinoma) than pancreatic head mass.*Primary sclerosing cholangitis*- Characterized by **multiple, diffuse, segmental strictures** alternating with normal duct segments, giving a **beaded appearance**.- This condition is an autoimmune process commonly associated with **ulcerative colitis**, not typically presenting as a solitary, malignant-appearing stricture.*Chronic pancreatitis*- Primary symptoms often include chronic severe **epigastric pain** and signs of **exocrine insufficiency** (steatorrhea) preceding jaundice.- Although it can cause benign strictures leading to jaundice, massive elevation of **CA 19-9** pointing to malignancy is rare without concurrent transformation (which would then be adenocarcinoma).
Irritable bowel syndrome UK Medical PG Question 10: A 41-year-old man presents with recurrent episodes of severe flushing and diarrhea. He develops bronchospasm during episodes. 5-HIAA is elevated. What is the primary tumor site likely to be?
- A. Lung
- B. Small bowel (Correct Answer)
- C. Pancreas
- D. Stomach
- E. Colon
Irritable bowel syndrome Explanation: ***Small bowel***- Midgut neuroendocrine tumors (NETs), typically originating in the **ileum**, are the most common source of metastases that produce the classic carcinoid syndrome (recurrent severe flushing, diarrhea, bronchospasm).- These tumors release large amounts of **serotonin**, which, when metastases bypass hepatic metabolism, causes systemic symptoms and elevates the urine excretion product, **5-HIAA**.*Lung*- Bronchial carcinoids can cause the syndrome, but the flushing is usually more **prolonged** and intense, and **carcinoid heart disease** is less common than with midgut tumors.- Primary lung tumors are less common than small bowel tumors to cause the full triad of severe flushing, profuse diarrhea, and bronchospasm.*Pancreas*- Pancreatic NETs, such as **insulinomas** or **gastrinomas**, typically cause syndromes related to their specific hormonal excess (e.g., hypoglycemia, peptic ulcers) rather than the classic serotonin-driven carcinoid syndrome.- While the pancreas can be a primary site, it is not the most likely cause of this specific generalized metastatic symptom constellation.*Stomach*- Gastric carcinoids often secrete **histamine**, leading to an atypical, often localized, flushing pattern, sometimes associated with specific dietary triggers.- This tumor site is less likely to produce the severe, systemic diarrhea and bronchospasm characteristic of a midgut serotonin-secreting tumor.*Colon*- Neuroendocrine tumors of the hindgut (colon and rectum), especially those in the rectum, rarely produce sufficient serotonin to cause the classic syndrome.- When colonic NETs do metastasize, they often present with local symptoms before generalized systemic signs of carcinoid syndrome appear.
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