1. Topic: Postoperative Pancreatitis

Correct Answer: D. All of the above

Explanation: Postoperative pancreatitis can occur after various surgical procedures, including bile duct surgery (commonly associated), cardiopulmonary surgeries (A), parathyroid procedures (B), and kidney transplants (C). These surgeries can lead to pancreatic injury or inflammation due to various mechanisms such as ischemia, trauma, or direct injury during surgical manipulation. Therefore, option D is correct as it encompasses all potential associations of postoperative pancreatitis beyond just bile duct surgery.

2. Topic: Warfarin Anticoagulation

Correct Answer: A. Prothrombin level

Explanation: Warfarin exerts its anticoagulant effect by inhibiting vitamin K-dependent clotting factors, primarily factors II, VII, IX, and X. The prothrombin time (PT) or International Normalized Ratio (INR) is used to monitor and adjust warfarin therapy. PT measures the extrinsic pathway of coagulation, primarily reflecting the levels of factors II, VII, and X. Monitoring the PT/INR helps ensure that the patient is within the therapeutic range for anticoagulation, balancing between efficacy in preventing thrombosis and minimizing bleeding risks. Therefore, option A is correct as it directly measures the effect of warfarin on clotting factors.

3. Topic: Rectal and Rectosigmoidal Cancer

Correct Answer: A. Melena

Explanation: Rectal and rectosigmoidal cancers commonly present with symptoms related to altered bowel habits and rectal bleeding. Melena, which refers to black, tarry stools resulting from digested blood, is a frequent manifestation of lower gastrointestinal bleeding, often seen in colorectal cancers. While constipation (B), tenesmus (C), diarrhea (D), and abdominal pain (E) can also occur, melena is specifically associated with bleeding from colorectal tumors due to its location and the nature of bleeding from these lesions. Therefore, option A is correct as it represents a hallmark symptom of rectal and rectosigmoidal cancer.

4. Topic: Osteoporosis

Correct Answer: C. Cancellous bone is rarely affected

Explanation: Osteoporosis is characterized by decreased bone density and quality, leading to an increased risk of fractures. Option C, stating that cancellous (spongy) bone is rarely affected, is incorrect. In fact, osteoporosis affects both cortical (compact) and cancellous bone, though cancellous bone tends to be more vulnerable due to its higher surface area and metabolic activity. Options A, B, D, and E are correct statements about osteoporosis: it causes numerous fractures annually (A), involves both quantitative and qualitative bone abnormalities (B), commonly results in hip and radius fractures (D), and is associated with estrogen loss in postmenopausal women (E). Therefore, the incorrect statement is C.

5. Topic: Cardiac Tamponade

Correct Answer: E. Cardiac tamponade

Explanation: Cardiac tamponade occurs when fluid (such as blood) accumulates in the pericardial sac, compressing the heart and impairing its ability to pump effectively. This leads to characteristic signs like engorged neck veins (due to impaired venous return), paradoxical pulse (a drop in systolic blood pressure >10 mmHg during inspiration), and hypotension (blood pressure of 60/10 mmHg in this case). Options A, B, C, and D are less likely diagnoses compared to cardiac tamponade given the classic clinical findings described. Therefore, the most likely diagnosis in this scenario is E.

6. Topic: Management of Cardiac Tamponade

Correct Answer: C. Immediate pericardiocentesis

Explanation: Immediate pericardiocentesis is the primary management for cardiac tamponade to relieve the pressure on the heart caused by the accumulated fluid in the pericardial sac. This procedure involves inserting a needle or catheter into the pericardial space to drain the fluid, thereby improving cardiac function and hemodynamics. Options A, B, D, and E may be considered in certain scenarios but do not address the urgent need to relieve the tamponade physiology as effectively as pericardiocentesis. Therefore, option C is the most appropriate and immediate management for this patient.

7. Topic: Urethral Injury

Correct Answer: E. Urethral strictures after surgical repair are seen

Explanation: Urethral strictures are a potential complication after urethral injury and repair, especially if there is significant scarring or improper healing. However, strictures are not uniformly seen in all cases of urethral injury after surgical repair. They may occur in a subset of patients depending on the severity and nature of the injury. Options A, B, C, and D are correct statements regarding urethral injuries: A) Injury to the membranous urethra often results from pelvic fractures; B) Bulbous urethra can be injured due to instrumentation; C) Incomplete urethral disruption may still allow some urine passage; D) Rectal examination can reveal an upwardly displaced prostate, indicating possible urethral injury. Therefore, option E is incorrect as strictures are not universally observed after surgical repair of urethral injuries.

8. Topic: Bone Tumors

Correct Answer: C. Osteogenic carcinoma (Osteosarcoma)

Explanation: Osteogenic carcinoma, or osteosarcoma, is a primary malignant bone tumor that often presents with pain, tenderness, and swelling at the affected site. It commonly occurs around the knee joint in adolescents and young adults. Limitation of motion can occur due to pain and mechanical obstruction caused by the tumor. Fibrosarcoma (option B) and osteochondroma (option D) typically present differently and are less likely in this clinical context. Brodie’s abscess (option E) usually manifests as localized bone pain with signs of abscess formation. Growing pains (option A) are typically non-specific and do not present with localized swelling and limitation of motion. Therefore, the most likely diagnosis based on the symptoms described is osteosarcoma.

9. Topic: Osteosarcoma

Correct Answer: A. Lymphatic dissemination is common

Explanation: Osteosarcoma primarily metastasizes hematogenously rather than through lymphatic dissemination. It often metastasizes early to the lungs (option B) due to its propensity for vascular spread. Treatment typically involves surgical resection (option C) of the primary tumor along with chemotherapy. Radiographically, osteosarcoma presents with characteristic destructive lesions involving the metaphyses of long bones (option D). Therefore, lymphatic dissemination (option A) is not a common feature of osteosarcoma, making it the incorrect statement in this context.

10. Topic: Fluid Management in Burns

Correct Answer: C. 15 litres of Ringer’s lactate

Explanation: In the initial management of severe burns, aggressive fluid resuscitation is crucial to maintain tissue perfusion and prevent hypovolemic shock. The Parkland formula is commonly used to calculate the fluid requirement over the first 24 hours, which is typically 4 ml/kg/% total body surface area (TBSA) burned. Half of the calculated fluid volume is administered in the first 8 hours, and the remaining half over the next 16 hours.

11. Topic: Hypospadias

Correct Answer: D. All of the above

Explanation: Hypospadias is a congenital condition where the urethral meatus opens on the ventral side of the penis rather than at the tip. It is associated with several features:A. Ventral displacement of the urethral meatus: This is a characteristic feature of hypospadias where the opening of the urethra is located on the underside of the penis.B. High incidence of cryptorchidism: There is an increased likelihood of concurrent undescended testes (cryptorchidism) in individuals with hypospadias. C. The degree of hypospadias requires repair: The severity of hypospadias varies, and surgical repair is often necessary to correct the abnormal positioning of the urethral opening. Therefore, all the statements (A, B, and C) are correct regarding hypospadias, making option D the correct answer.

12. Topic: Gastrointestinal Radiographs

Correct Answer: B. Tumor of the head of the pancreas

Explanation: On gastrointestinal radiographs, an enlargement of the duodenal sweep with downward and rightward displacement is often indicative of a tumor of the head of the pancreas. This displacement occurs due to the mass effect of the tumor pushing the duodenum downward and to the right. This finding is characteristic and helps in identifying the location and nature of the pancreatic lesion during radiological examinations.

13. Topic: Saphenous Vein Ligation for Varicose Veins

Correct Answer: B. Circumflex superficial vein

Explanation: During saphenous vein ligation for varicose veins, the circumflex superficial vein should not be ligated. This vein is important because it can serve as an important collateral pathway in case of venous obstruction or during surgical procedures involving the saphenous vein. Ligating this vein unnecessarily can lead to complications or compromise venous drainage in the lower extremities.

14. Topic: Traumatic Subdural Hematoma

Correct Answer: C. A severe or mild head injury

Explanation: Traumatic subdural hematoma typically occurs as a result of head injury, whether severe or mild. The forceful impact on the head can cause tearing of blood vessels, most commonly the bridging veins that connect the brain surface to the dural sinuses. This tearing leads to bleeding between the dura mater and arachnoid mater layers of the meninges, resulting in the accumulation of blood known as subdural hematoma.

15. Topic: Gastro-jejuno-colic Fistula

Correct Answer: D. Irritation caused by gas and colonic contents entering the stomach and duodenum

Explanation: A gastro-jejuno-colic fistula is an abnormal communication between the stomach, jejunum (part of the small intestine), and colon (large intestine). This condition allows contents from one part of the gastrointestinal tract to enter another where they normally should not, leading to various symptoms.

16. Topic: Nerve Injury in Shoulder Dislocation

Correct Answer: B. The axillary nerve

Explanation: Shoulder dislocations can lead to nerve injuries due to the trauma and stretching involved. The axillary nerve, which innervates the deltoid and teres minor muscles and provides sensation to the shoulder joint, is particularly vulnerable in posterior shoulder dislocations or anterior dislocations with an associated fracture of the surgical neck of the humerus.

17. Topic: Complications of Massive Pelvic Fracture

Correct Answer: C. Massive blood loss

Explanation: Massive pelvic fractures are associated with significant vascular injury, leading to massive blood loss. The pelvis contains numerous large blood vessels, including the iliac arteries and veins, which can be lacerated or disrupted during traumatic injuries.

18. Topic: Enlarged Mediastinum after Chest Trauma

Correct Answer: A. Partial interruption of the aorta

Explanation: An enlarged mediastinum following blunt chest trauma, especially after forceful impact against the steering wheel, suggests aortic injury. This injury can lead to partial interruption or tear of the aorta, resulting in blood leakage into the mediastinal space. The mediastinum is enlarged due to hematoma formation or vascular disruption.

19. Topic: Indications for Surgery in Prostate Adenoma

Correct Answer: B. There is frank dysuria

Explanation: Surgery for prostate adenoma (benign prostatic hyperplasia, BPH) is indicated primarily when patients experience severe symptoms that significantly affect their quality of life and conservative management fails to alleviate symptoms. Frank dysuria, which refers to painful or difficult urination, indicates severe urinary obstruction due to prostate enlargement.

20. Topic: Bacterial Sepsis Risk in Splenectomized Individuals

Correct Answer: C. Salmonella

Explanation: Splenectomized individuals, lacking the spleen’s immune functions, are particularly vulnerable to severe bacterial infections, especially from encapsulated bacteria like Salmonella. The spleen plays a crucial role in filtering and clearing encapsulated bacteria from the bloodstream. Without a spleen, individuals are less able to mount an effective immune response against these pathogens, leading to an increased risk of bacteremia and sepsis, particularly from Salmonella species.

21. Topic: Intestinal Obstruction in the Elderly

Correct Answer: B. Hirschsprung’s disease (megacolon)

Explanation: Intestinal obstruction in the elderly typically results from acquired conditions rather than congenital anomalies like Hirschsprung’s disease, which presents in childhood. Common causes in the elderly include colonic cancer causing colonic occlusion (A), small bowel obstruction due to biliary ileus (C), Ogilvie syndrome (D), and colonic pseudo-obstruction from fecal impaction (E). Hirschsprung’s disease, characterized by megacolon, is a congenital disorder that is usually diagnosed and managed in infancy or childhood, not in elderly patients presenting with intestinal obstruction.

22. Topic: Upper Gastrointestinal Bleeding

Correct Answer: D. Diagnosis endoscopy is best done within the first 24 hours

Explanation: In patients with upper gastrointestinal bleeding, early diagnosis and intervention are crucial. Endoscopy performed within the first 24 hours allows for prompt identification and management of the bleeding source, which can significantly improve outcomes and reduce the need for surgical intervention.

23. Topic: Peptic Ulcer Disease

Correct Answer: B. Pyloric stenosis is the least common complication

Explanation: In peptic ulcer disease, complications like hemorrhage, perforation, and obstruction are relatively common, with pyloric stenosis being the least common among them. This makes B the correct answer. Barium studies (A) may not always reliably detect ulcers, surgery (C) is often reserved for severe cases, a drainage procedure (D) is sometimes necessary after truncal vagotomy, and subdiaphragmatic gas (E) may not always be visible after perforation.

24. Topic: Diabetic Foot Ulcer Management in Diabetic Ketoacidosis

Correct Answer: C. The request for a surgical consultation for a surgical procedure

Explanation: In diabetic patients presenting with diabetic ketoacidosis and a fluctuating erythematous mass over a small foot ulcer, prompt surgical consultation is essential. Diabetic foot ulcers complicated by infection require early surgical intervention, such as debridement or drainage, to control the infection and prevent systemic complications like worsening ketoacidosis. Surgical consultation ensures timely assessment and appropriate management, crucial for improving outcomes and preventing further morbidity in diabetic patients.

25. Topic: Assessment of Gastrointestinal Bleeding Severity

Correct Answer: E. Blood pressure in the supine and standing position

Explanation: In evaluating the severity of gastrointestinal bleeding, changes in blood pressure from supine to standing position (orthostatic hypotension) provide a sensitive indicator. This reflects the volume status and potential for significant blood loss. Hemoglobin level (A) is an important marker but may not immediately reflect acute changes. Systolic blood pressure (B) and pulse rate (C) are vital signs that can indicate acute hemorrhage but may not fully capture the extent of blood loss. Volume of vomit/melena (D) gives direct visual assessment but does not quantify the severity of bleeding comprehensively. Orthostatic blood pressure changes (E) are particularly useful in assessing volume depletion and guiding resuscitative efforts in gastrointestinal bleeding.

26. Topic: Anuria Following Total Colostomy

Correct Answer: E. Urethral avulsions

Explanation: Complete anuria following total colostomy, especially after profuse bleeding from diverticula, is most likely due to urethral avulsions (E). This condition involves the traumatic separation of the urethra from its attachment, leading to obstruction of urine flow. Options A, B, and D involve systemic issues or fluid management complications that would not directly cause anuria in this scenario. Acute tubular necrosis (C) typically manifests differently and is less likely in the absence of systemic hypoperfusion or nephrotoxic insults. Urethral avulsions are a direct mechanical complication that can lead to the cessation of urine flow.

27. Topic: Pseudocysts of the Pancreas

Correct Answer: D. They all require surgery to heal

Explanation: Pseudocysts of the pancreas are encapsulated collections of pancreatic fluid that typically develop as a complication of pancreatitis. The correct answer is D because not all pseudocysts require surgery for healing. Management depends on the size, symptoms, and complications. Many smaller pseudocysts can resolve spontaneously or with conservative management such as observation, drainage procedures (percutaneous or endoscopic), or internal drainage into a hollow viscus or the retroperitoneal space (E). Surgery is reserved for larger or symptomatic pseudocysts that do not respond to less invasive measures. Options A, B, and C describe features and locations of pseudocysts that are generally true.

28. Topic: Truncal Vagotomy for Duodenal Ulcer Disease

Correct Answer: E. Gastrin production is significantly reduced

Explanation: Truncal vagotomy is a surgical procedure used to treat duodenal ulcer disease by severing the vagus nerve to reduce gastric acid secretion. The correct answer is E because truncal vagotomy does not significantly reduce gastrin production. Instead, it primarily reduces gastric acid secretion by affecting parietal cells. Options A, B, C, and D describe possible outcomes and considerations after truncal vagotomy, which are generally true.

29. Topic: Chest Tube Placement for Pneumothorax

Correct Answer: D. Prolonged collapse allows the formation of a fibrin sheet that makes late expansion more difficult

Explanation: The correct answer is D because chest tube placement for a pneumothorax aims to relieve pressure in the pleural space promptly to prevent complications such as mediastinal shift (C), impaired venous return (C), infection (B), and the accumulation of fluid (E). Option A refers to a tension pneumothorax rather than a simple pneumothorax but does not describe the least likely reason for placing a chest tube.

30. Topic: Pericardial Tamponade

Correct Answer: D. Obstructed venous return to the heart

Explanation: Pericardial tamponade following penetrating injuries can compress the heart due to accumulated fluid in the pericardial sac, resulting in obstructed venous return to the heart (D). This compression reduces cardiac output and can lead to hemodynamic compromise. ECG changes (A) are also commonly observed due to the pressure on the heart, but they are not the primary effect described in the question. Bradycardia (B) can occur as a compensatory response, and central venous pressure (C) is typically increased rather than decreased in tamponade. Option E is unrelated to the effects of pericardial tamponade.

31. Topic: Shoulder Dislocation and Axillary Nerve Injury

Correct Answer: C. The axillary nerve injury

Explanation: After a closed reduction of a shoulder dislocation, complications such as axillary nerve injury can occur due to trauma or traction during the dislocation process. The axillary nerve supplies the deltoid muscle, and its injury can lead to muscle atrophy and anesthesia in the area of deltoid insertion (C). Associated fractures of the greater tuberosity (A) can also occur with shoulder dislocations but typically do not cause anesthesia or significant deltoid atrophy. Brachial plexus traction injuries (B) are less likely in isolated shoulder dislocations without severe trauma. Cervical avulsion (D) is a severe injury of the spinal cord roots and is unlikely in this scenario. Atrophy following immobilization (E) may occur but typically would not cause anesthesia at the deltoid insertion site.

32. Topic: Recurrent Laryngeal Nerve Injury During Thyroid Lobectomy

Correct Answer: B. The left vocal cord is at the medial level

Explanation: During thyroid lobectomy, the recurrent laryngeal nerve (RLN) can be at risk of injury due to its close anatomical proximity to the thyroid gland. Specifically, on the left side, the RLN loops around the aortic arch and ascends towards the larynx. If the left vocal cord is found at the medial level (B), it suggests that the RLN has been transected or damaged during the surgery. This positioning indicates a potential injury to the nerve, leading to vocal cord dysfunction

33. Topic: Fever After Cholecystectomy

Correct Answer: D. A leaky cystic duct stump

Explanation: After a cholecystectomy (removal of the gallbladder), a high fever can indicate several potential complications. A leaky cystic duct stump (D) is a common cause of fever post-operatively due to bile leakage into the peritoneal cavity, which can lead to infection and inflammation. This complication requires prompt identification and intervention to prevent further complications.

34. Topic: Upper Arm Gunshot Wound

Correct Answer: C. The median nerve

Explanation: Injuries to the median nerve (C) following a gunshot wound to the upper third of the arm can result in specific neurological deficits, including atrophy of the thenar eminence (associated with thumb muscles) and inability to flex the distal phalanx of the index finger. These symptoms are characteristic of median nerve injury, affecting motor function in the forearm and hand.

35. Topic: Thumb Interphalangeal Joint Injury

Correct Answer: A. Colles fracture

Explanation: A Colles fracture (A) is a type of distal radius fracture that can lead to a late complication known as the “dinner fork” deformity due to dorsal displacement of the distal fragment. This injury can affect the extensor pollicis longus tendon, resulting in a complete inability to actively extend the thumb interphalangeal joint.

36. Topic: Assessment of Genitourinary Tract Integrity in Pelvic Trauma

Correct Answer: D. Intravenous pyelography

Explanation: Intravenous pyelography (IVP) (D) involves injecting a contrast dye intravenously to visualize the kidneys, ureters, and bladder on X-ray imaging. However, in the context of a severely crushed pelvis and profound shock, IVP may not be immediately helpful or feasible for assessing the intact integrity of the genitourinary tract.

37. Topic: Management of Abdominal Stab Wounds

Correct Answer: C. Exploratory laparotomy

Explanation: In the scenario of a police officer stabbed multiple times in the abdomen with penetrating injuries through the rectus abdominis sheaths and anterior abdominal wall, the appropriate next step in management is exploratory laparotomy (C).

38. Topic: Management of Traumatic Brain Injury

Correct Answer: A. Immediate surgical intervention

Explanation: In the case of a patient who falls down stairs, develops dizziness initially, then becomes drowsy with left hemiplegia, and subsequently becomes comatose with a scalp contusion, the presentation suggests a significant traumatic brain injury (TBI)

39. Topic: Disseminated Intravascular Coagulation (DIC)

Correct Answer: C. Lack of vitamin C

Explanation: Disseminated Intravascular Coagulation (DIC) is a complex disorder characterized by widespread activation of clotting factors throughout the bloodstream, leading to both thrombosis and hemorrhage. Several factors contribute to the pathophysiology of DIC: Incorrect Answer: C (Lack of vitamin C): Vitamin C deficiency (scurvy) primarily affects collagen synthesis and connective tissue integrity rather than directly influencing the coagulation cascade involved in DIC. While vitamin C is essential for wound healing and maintaining vascular integrity, it is not a direct factor in the pathogenesis of DIC.

40. Topic: Arteriovenous Fistula (AV Fistula)

Correct Answer: B. A significant rise in diastolic pressure

Explanation: The establishment of an arteriovenous fistula leads to increased cardiac output, resulting in effects such as heart acceleration (A), a continuous vibratory quiver (C), and dilation and hypertrophy of the heart (D). However, a significant rise in diastolic pressure (B) is not typically observed; instead, diastolic pressure may actually decrease due to the reduced peripheral resistance. This makes B the correct answer as it is not an effect of an arteriovenous fistula.

41. Topic: Pyloric Ulcer

Correct Answer: D. A medical regimen including overnight stomach decompression and a modified form of diet

Explanation: For a patient presenting with symptoms suggestive of a pyloric ulcer, such as epigastric pain relieved by food, nocturnal pain, and vomiting predominantly at night, the initial preferred treatment involves a medical approach. This includes overnight stomach decompression to alleviate gastric retention and implementing a modified diet to manage symptoms effectively.

42. Topic: Vesicoureteral Reflux

Correct Answer: D. All of the above

Explanation: Vesicoureteral reflux (VUR) is diagnosed based on various criteria, including recurrent urinary tract infections (A), objective reflux visualized during pre-void cystography (B), and abnormalities in the configuration of the ureteral orifice observed during cystoscopy (C). These factors collectively contribute to confirming the presence and severity of VUR in patients, guiding further management decisions.

43. Topic: Neurogenic Bladder

Correct Answer: D. All of the above

Explanation: A neurogenic bladder, which results from impaired nerve supply to the bladder, can lead to various complications. These include urinary tract infections (A) due to incomplete bladder emptying, formation of calculi (B) from stagnant urine, and hydronephrosis (C) from increased pressure in the urinary system. Therefore, all these conditions (D) are common complications of a neurogenic bladder, making D the correct answer.

44. Topic: Ureteral Injury

Correct Answer: A. Most ureteral injuries are iatrogenic

Explanation: Ureteral injuries are often iatrogenic, meaning they result from medical procedures. Common causes include surgical interventions involving the pelvic organs, such as hysterectomy, and other pelvic surgeries where the ureter can inadvertently be damaged or obstructed. Recognizing the risk factors and ensuring careful surgical technique can help minimize these injuries.

45. Topic: Assessment for Tonsillectomy

Correct Answer: A. History of previous bleeding

Explanation: Before performing a tonsillectomy, assessing the patient’s history of previous bleeding episodes is crucial. This includes inquiring about any instances of prolonged bleeding after minor cuts or dental procedures, as well as any family history of bleeding disorders or abnormal bleeding tendencies. A positive history of bleeding may necessitate further evaluation, such as coagulation studies, to ensure safe management during and after the procedure.

46. Topic: Surgical Intervention for Paraplegia

Correct Answer: D. Epidural abscess

Explanation: Paraplegia that develops suddenly in a 37-year-old man raises concern for a potentially compressive spinal lesion, such as an epidural abscess. Immediate surgical intervention is crucial in this scenario to relieve pressure on the spinal cord and prevent permanent neurological damage. Epidural abscesses can rapidly progress and cause significant neurological deficits if not promptly treated with surgical drainage and antibiotic therapy.

47. Topic: Delayed Gastric Emptying

Correct Answer: E. All of the above

Explanation: Delayed gastric emptying, also known as gastroparesis, can be associated with several conditions. Myxedema (A), resulting from severe hypothyroidism, can slow gastric motility. Hypocalcemia (B) and hypokalemia (C) can affect smooth muscle function, leading to delayed gastric emptying. Diabetes mellitus (D) is a well-known cause of gastroparesis due to autonomic neuropathy. Since all these conditions (E) can be associated with delayed gastric emptying, E is the correct answer.

48. Topic: Ischemic Colitis

Correct Answer: D. Ischemic colitis

Explanation: Ischemic colitis presents with cramping abdominal pain, typically left-sided, and may be associated with bloody diarrhea. Examination findings often include mild abdominal distension and tenderness without peritoneal signs. Febrile episodes can occur due to inflammation. This condition is often diagnosed based on clinical presentation and imaging studies, showing ischemic changes in the affected colonic segment. Carcinoma of the sigmoid colon (A) would typically present with more chronic symptoms and might not cause acute bloody diarrhea without peritoneal signs. Diverticulitis (B) presents with localized pain, fever, and signs of inflammation, often associated with diverticula. Diverticulosis (C) is usually asymptomatic unless complicated by diverticulitis or bleeding. Intussusception (E) is rare in adults and presents with severe abdominal pain and signs of bowel obstruction.

49. Topic: Ischemic Colitis

Correct Answer: B. Colonoscopy

Explanation: Colonoscopy is the most likely diagnostic investigation to confirm the diagnosis of ischemic colitis. It allows direct visualization of the colonic mucosa, assessment of the extent of ischemic changes, and the possibility of obtaining biopsy samples for histological examination. X-ray of the abdomen without preparation (A) may show nonspecific signs but is not as diagnostic as colonoscopy. Ultrasound (C) is not typically used for diagnosing ischemic colitis. Upper gastrointestinal endoscopy (D) is used to examine the upper gastrointestinal tract and is not relevant for evaluating colonic ischemia. Therefore, colonoscopy is the preferred method for definitive diagnosis in suspected cases of ischemic colitis.

50. Topic: Ischemic Colitis

Correct Answer: E. All of the above

Explanation: Ischemic colitis can be associated with various predisposing factors and conditions. Cardiac arrhythmias (A) can lead to embolic events affecting colonic blood supply. Radiation enteritis (B) can cause chronic vascular changes predisposing to ischemia. Distal colon occlusion (C) can compromise blood flow to the affected segment. Collagenosis (D), such as autoimmune diseases like systemic lupus erythematosus, can predispose to vascular abnormalities and ischemic events. Therefore, all of the listed factors (A, B, C, D) are potential predisposing factors or associated conditions in the case of ischemic colitis.