A 62-year-old man undergoes emergency laparotomy for perforated sigmoid diverticulitis. Intraoperatively, there is faeculent peritonitis with widespread contamination. A Hartmann's procedure is performed. Which of the following factors according to the Mannheim Peritonitis Index would contribute most significantly to predicting mortality in this patient?
Q42
A 36-year-old woman who is 36 weeks pregnant presents with sudden onset severe right upper quadrant pain and vomiting. She has had a headache for the past two days. Examination reveals blood pressure 165/105 mmHg, tenderness in the right upper quadrant with guarding, and hyperreflexia. Blood tests show: platelets 85 × 10⁹/L, ALT 320 U/L, AST 298 U/L, LDH 650 U/L, and blood film shows schistocytes. What is the most likely diagnosis?
Q43
Which of the following best describes the anatomical reason why perforation of a posterior duodenal ulcer typically does NOT result in pneumoperitoneum on erect chest radiograph?
Q44
A 55-year-old man with no previous abdominal surgery presents with a 5-day history of progressive abdominal distension, cramping pain, and absolute constipation. He denies nausea or vomiting. Plain abdominal radiograph shows a massively dilated loop of bowel with haustra visible only partially around the circumference of the dilated segment, arising from the left iliac fossa and extending to the right upper quadrant. Which of the following is the most likely diagnosis?
Q45
A 44-year-old woman presents with sudden onset severe right upper quadrant pain radiating to the right shoulder tip. She has had multiple episodes of biliary colic but has declined previous surgical intervention. Examination reveals peritonism in the right upper quadrant. CT imaging shows pneumobilia and a dilated stomach. A 3cm gallstone is identified in the proximal jejunum. Which of the following is the most appropriate definitive surgical management?
Q46
A 74-year-old man presents with a 5-day history of colicky abdominal pain, distension, and absolute constipation. He has not had any previous abdominal surgery. Plain abdominal radiograph shows grossly dilated large bowel with loss of haustral markings, predominantly in the left colon, and a dilated caecum measuring 11 cm. CT confirms large bowel obstruction with a 4 cm circumferential mass in the sigmoid colon and no evidence of perforation or distant metastases. What is the most appropriate definitive surgical management for this patient?
Q47
A 51-year-old woman with Crohn's disease presents with a 24-hour history of severe cramping abdominal pain and bilious vomiting. She has had multiple previous resections including ileocaecal resection. CT shows dilated small bowel loops (4.5 cm) with thickened terminal ileum and a transition point with proximal bowel wall oedema and mesenteric fat stranding. There is no free air. She is started on IV fluids and nasogastric decompression. At 48 hours, she develops increased pain, persistent tachycardia (HR 118 bpm), and rising inflammatory markers (WCC 17 × 10⁹/L, CRP 185 mg/L). What feature in her presentation most strongly suggests the need for urgent surgical intervention?
Q48
A 57-year-old man undergoes emergency laparotomy for perforated sigmoid diverticulitis with faecal peritonitis. At surgery, a 2 cm perforation is found with widespread faecal contamination. His pre-operative observations showed BP 95/60 mmHg, HR 115 bpm, and temperature 38.9°C. Intra-operatively, after washout, what is the most appropriate surgical management according to current evidence-based guidelines?
Q49
A 68-year-old man with atrial fibrillation presents with a 6-hour history of sudden onset severe generalized abdominal pain that is disproportionate to examination findings. He passed one episode of bloody diarrhoea. His pulse is irregularly irregular at 98 bpm. Abdominal examination reveals mild diffuse tenderness without guarding. Blood tests show WCC 16.5 × 10⁹/L, lactate 4.8 mmol/L, and metabolic acidosis on VBG. What CT finding would most specifically confirm the suspected diagnosis?
Q50
A 63-year-old man with metastatic colorectal cancer on palliative chemotherapy presents with a 4-day history of colicky abdominal pain, distension, and vomiting. He has not opened his bowels for 5 days. CT imaging shows dilated small bowel loops up to 4 cm with a transition point at the terminal ileum where there is peritoneal disease. Conservative management with IV fluids and nasogastric decompression is commenced. After 48 hours, his symptoms partially improve but obstruction persists. What is the most appropriate next intervention?
Acute Surgical Presentations UK Medical PG Practice Questions and MCQs
Question 41: A 62-year-old man undergoes emergency laparotomy for perforated sigmoid diverticulitis. Intraoperatively, there is faeculent peritonitis with widespread contamination. A Hartmann's procedure is performed. Which of the following factors according to the Mannheim Peritonitis Index would contribute most significantly to predicting mortality in this patient?
A. Organ failure at presentation (Correct Answer)
B. Age over 50 years
C. Female gender
D. Duration of symptoms less than 24 hours
E. Colonic origin of peritonitis
Explanation: ***Organ failure at presentation***
- In the **Mannheim Peritonitis Index (MPI)**, **organ failure** is the most significant predictor as it is assigned the highest weight of **7 points**.
- Organ failure is defined by clinical criteria such as **shock**, **renal failure**, or **respiratory insufficiency**, correlating strongly with poor patient outcomes.
*Age over 50 years*
- While age over 50 years is a component of the MPI, it contributes **5 points** to the total score, which is less than organ failure.
- This patient is 62 years old, but his physiological state (organ failure) takes precedence in **mortality prediction** models.
*Female gender*
- According to the MPI, **female gender** is assigned **5 points** as a risk factor for mortality.
- Since the patient in this clinical scenario is male, this factor does not contribute to his specific MPI score.
*Duration of symptoms less than 24 hours*
- The MPI only assigns points (**4 points**) for a duration of peritonitis **greater than 24 hours**.
- Symptoms lasting less than 24 hours are considered a relatively favorable prognostic factor and do not add to the risk score.
*Colonic origin of peritonitis*
- Peritonitis originating from the **large bowel** (colonic) is assigned **4 points** in the scoring system.
- This carries less weight compared to non-colonic origins (which score 6 points) and is significantly less weighted than the presence of **organ failure**.
Question 42: A 36-year-old woman who is 36 weeks pregnant presents with sudden onset severe right upper quadrant pain and vomiting. She has had a headache for the past two days. Examination reveals blood pressure 165/105 mmHg, tenderness in the right upper quadrant with guarding, and hyperreflexia. Blood tests show: platelets 85 × 10⁹/L, ALT 320 U/L, AST 298 U/L, LDH 650 U/L, and blood film shows schistocytes. What is the most likely diagnosis?
A. Acute cholecystitis
B. HELLP syndrome with subcapsular liver haematoma (Correct Answer)
C. Perforated peptic ulcer
D. Acute appendicitis with atypical location
E. Acute fatty liver of pregnancy
Explanation: ***HELLP syndrome with subcapsular liver haematoma***- The patient exhibits classic features of **HELLP syndrome**: **Hemolysis** (schistocytes, elevated LDH), **Elevated Liver enzymes** (ALT/AST), and **Low Platelets** (thrombocytopenia) in late pregnancy.- Severe right upper quadrant pain accompanied by **hypertension** and **guarding** suggests **distension or rupture of the liver capsule**, a life-threatening complication of pre-eclampsia.*Acute cholecystitis*- While it causes RUQ pain and vomiting, it does not explain the **hypertension**, **thrombocytopenia**, or the presence of **schistocytes** indicative of microangiopathic hemolytic anemia.- **Fever** and a normal blood pressure are more typical for cholecystitis, whereas this patient has clear systemic **pre-eclamptic features**.*Perforated peptic ulcer*- This typically presents with **pneumoperitoneum** and sudden, generalized peritonitis rather than isolated RUQ pain with **hyperreflexia** and hypertension.- It would not cause the characteristic laboratory triad of **low platelets**, elevated transaminases, and **fragmented red cells** seen on the blood film.*Acute appendicitis with atypical location*- Appendicitis in pregnancy can present in the RUQ as the **gravid uterus displaces the appendix**, but it does not cause **hypertension** or **hemolysis**.- The inflammatory markers might be elevated, but the specific **multi-organ involvement** (liver and hematologic system) points away from a localized infectious process.*Acute fatty liver of pregnancy*- Often presents with **jaundice**, severe **hypoglycemia**, and prolonged **clotting times** (PT/APTT), which are not the primary findings presented here.- While it occurs in the third trimester, it does not typically feature the **microangiopathic hemolytic anemia** (schistocytes) characteristic of HELLP syndrome.
Question 43: Which of the following best describes the anatomical reason why perforation of a posterior duodenal ulcer typically does NOT result in pneumoperitoneum on erect chest radiograph?
A. Posterior duodenal ulcers typically seal spontaneously before significant air leak occurs
B. The posterior location causes immediate adhesion formation preventing air leak
C. The posterior duodenum is retroperitoneal, so perforation releases air into the retroperitoneum rather than the peritoneal cavity (Correct Answer)
D. The transverse mesocolon prevents air from rising to the subphrenic space
E. The small volume of air released is insufficient to be detected radiographically
Explanation: ***The posterior duodenum is retroperitoneal, so perforation releases air into the retroperitoneum rather than the peritoneal cavity***- The **second and third parts** of the duodenum are largely **retroperitoneal structures**. Perforation in these posterior areas releases gastrointestinal contents, including air, into the **retroperitoneal space**.- Since the air does not enter the **peritoneal cavity**, it cannot accumulate under the **diaphragm** to be visible as **free air** on an erect chest radiograph, which is the classic sign of intraperitoneal perforation.*Posterior duodenal ulcers typically seal spontaneously before significant air leak occurs*- While some perforations can be sealed, this is not a common or reliable mechanism, especially for ulcers that have eroded significantly enough to perforate.- Posterior duodenal ulcers are more notorious for eroding into the **gastroduodenal artery**, leading to **massive hemorrhage**, rather than spontaneously sealing.*The posterior location causes immediate adhesion formation preventing air leak*- **Adhesions** are typically a chronic process resulting from inflammation, not an immediate event upon acute perforation that would reliably prevent air leak.- Even if some containment were to occur, the primary reason for absence of pneumoperitoneum is the **retroperitoneal location** of the perforation, not instantaneous adhesion formation.*The transverse mesocolon prevents air from rising to the subphrenic space*- The **transverse mesocolon** divides the peritoneal cavity but does not prevent free intraperitoneal air from rising to the **subphrenic space** if it originates within the peritoneal cavity.- The issue with posterior duodenal perforations is that the air is released *outside* the **peritoneal cavity** altogether, making the transverse mesocolon irrelevant to its ascent to the subphrenic space.*The small volume of air released is insufficient to be detected radiographically*- Even a **small volume** of free intraperitoneal air (e.g., 1-2 mL) can often be detected on a properly performed erect chest X-ray if it's within the **peritoneal cavity**.- The problem isn't the volume of air, but rather its **anatomical location** within the **retroperitoneum**, where it tracks along fascial planes and does not accumulate under the diaphragm.
Question 44: A 55-year-old man with no previous abdominal surgery presents with a 5-day history of progressive abdominal distension, cramping pain, and absolute constipation. He denies nausea or vomiting. Plain abdominal radiograph shows a massively dilated loop of bowel with haustra visible only partially around the circumference of the dilated segment, arising from the left iliac fossa and extending to the right upper quadrant. Which of the following is the most likely diagnosis?
A. Small bowel obstruction due to adhesions
B. Toxic megacolon
C. Sigmoid volvulus (Correct Answer)
D. Caecal volvulus
E. Large bowel obstruction due to colorectal carcinoma
Explanation: ***Sigmoid volvulus*** - The radiograph describes a massive, dilated loop of bowel arising from the **left iliac fossa** and extending towards the **right upper quadrant**, which is the classic **'coffee bean'** or **'inverted U'** sign. - The presence of **haustra** only partially crossing the bowel wall and the patient's **absolute constipation** for 5 days support a distal large bowel obstruction caused by torsion.*Small bowel obstruction due to adhesions* - This typically presents with **valvulae conniventes** that span the entire width of the bowel, unlike the partial haustra seen in this case. - Significantly, the patient has **no previous abdominal surgery**, making **adhesions** a highly unlikely cause of obstruction.*Toxic megacolon* - This condition is a complication of inflammatory bowel disease or infection and usually presents with severe **systemic toxicity**, fever, and tachycardia, which are absent here. - The dilation in **toxic megacolon** is typically generalized and lacks the specific twisted **loop orientation** seen in volvulus.*Caecal volvulus* - A **caecal volvulus** typically arises from the **right lower quadrant** and often moves toward the **left upper quadrant** or epigastrium. - It involves the **caecum** and often shows a single fluid level with a distinctive **'comma' or 'fetal' shape** rather than an inverted U shape.*Large bowel obstruction due to colorectal carcinoma* - While a common cause of obstruction, malignancy usually results in a more gradual **distension of the entire proximal colon** rather than a single massive, isolated loop. - Carcinoma does not typically produce the characteristic **'coffee bean' appearance** that is diagnostic of a sigmoid volvulus.
Question 45: A 44-year-old woman presents with sudden onset severe right upper quadrant pain radiating to the right shoulder tip. She has had multiple episodes of biliary colic but has declined previous surgical intervention. Examination reveals peritonism in the right upper quadrant. CT imaging shows pneumobilia and a dilated stomach. A 3cm gallstone is identified in the proximal jejunum. Which of the following is the most appropriate definitive surgical management?
A. Enterolithotomy alone via enterotomy at the obstruction site (Correct Answer)
B. Enterolithotomy with simultaneous cholecystectomy and fistula repair
C. Endoscopic retrieval of the gallstone
D. Small bowel resection with primary anastomosis
E. Percutaneous drainage of the gallbladder with delayed stone extraction
Explanation: ***Enterolithotomy alone via enterotomy at the obstruction site*** - This patient presents with **gallstone ileus**, characterized by **pneumobilia** and a gallstone causing small bowel obstruction, indicating a **cholecystoenteric fistula**. - **Enterolithotomy** is the definitive management in the acute setting, as it relieves the life-threatening obstruction while minimizing operative time and **morbidity** in potentially unstable patients. *Enterolithotomy with simultaneous cholecystectomy and fistula repair* - Performing a **simultaneous cholecystectomy** and fistula repair significantly increases the **operative time** and risk of **postoperative complications** and mortality compared to simple enterolithotomy. - This more extensive procedure is usually reserved for select **hemodynamically stable** patients or performed as a staged, elective procedure if recurrent symptoms warrant it. *Endoscopic retrieval of the gallstone* - Endoscopic retrieval is generally ineffective for stones that have reached the **proximal jejunum** or beyond, as they are typically out of reach for a standard gastroduodenoscope. - This method is primarily considered for **Bouveret syndrome**, where the gallstone obstructs the gastric outlet or duodenum. *Small bowel resection with primary anastomosis* - **Small bowel resection** is only indicated if there is evidence of **bowel ischemia**, necrosis, perforation, or irreversible damage at the site of impaction. - In the absence of these complications, a simple **longitudinal enterotomy** for stone extraction with primary closure is preferred to preserve bowel length and reduce surgical trauma. *Percutaneous drainage of the gallbladder with delayed stone extraction* - **Percutaneous cholecystostomy** addresses acute cholecystitis but does not resolve the **mechanical small bowel obstruction** caused by the impacted gallstone in the jejunum. - The immediate priority is to relieve the small bowel obstruction, which this procedure fails to achieve, making it an inappropriate primary management.
Question 46: A 74-year-old man presents with a 5-day history of colicky abdominal pain, distension, and absolute constipation. He has not had any previous abdominal surgery. Plain abdominal radiograph shows grossly dilated large bowel with loss of haustral markings, predominantly in the left colon, and a dilated caecum measuring 11 cm. CT confirms large bowel obstruction with a 4 cm circumferential mass in the sigmoid colon and no evidence of perforation or distant metastases. What is the most appropriate definitive surgical management for this patient?
A. Right hemicolectomy to decompress the dilated caecum
B. Segmental sigmoid resection with primary anastomosis
C. Subtotal colectomy with end ileostomy
D. Emergency Hartmann's procedure with end colostomy
E. Endoscopic colonic stenting as a bridge to elective surgery (Correct Answer)
Explanation: ***Endoscopic colonic stenting as a bridge to elective surgery***
- This approach is ideal for an **obstructing left-sided colorectal cancer** without perforation, as it converts an **emergency** into an **elective** procedure after decompression.
- It allows for **pre-operative optimization**, thorough **oncological staging**, and significantly increases the likelihood of a **primary anastomosis** while avoiding a permanent stoma.
*Right hemicolectomy to decompress the dilated caecum*
- A right hemicolectomy would not address the **primary pathology**, which is a circumferential mass located in the **sigmoid colon**.
- While the **caecum is dilated** (11 cm), decompression must target the site of the **distal obstruction** to be effective and curative.
*Segmental sigmoid resection with primary anastomosis*
- Performing a primary anastomosis in an **emergency setting** with an **unprepared, dilated bowel** carries a high risk of **anastomotic leak**.
- This procedure is generally avoided in the acute phase of **large bowel obstruction** due to the presence of significant **faecal loading** and wall edema.
*Subtotal colectomy with end ileostomy*
- This is an **extensive surgical procedure** that is usually reserved for cases with **multi-focal synchronous tumors** or an **imminent caecal perforation**.
- It is unnecessarily aggressive for a localized **sigmoid mass** when less invasive bridging options like **stenting** are available.
*Emergency Hartmann's procedure with end colostomy*
- Historically the standard of care, it involves **resecting the sigmoid colon** and creating a **permanent or temporary stoma**, which carries significant morbidity in elderly patients.
- Many patients who undergo Hartmann's procedure never have their **stoma reversed**, leading to a lower **quality of life** compared to elective primary anastomosis after stenting.
Question 47: A 51-year-old woman with Crohn's disease presents with a 24-hour history of severe cramping abdominal pain and bilious vomiting. She has had multiple previous resections including ileocaecal resection. CT shows dilated small bowel loops (4.5 cm) with thickened terminal ileum and a transition point with proximal bowel wall oedema and mesenteric fat stranding. There is no free air. She is started on IV fluids and nasogastric decompression. At 48 hours, she develops increased pain, persistent tachycardia (HR 118 bpm), and rising inflammatory markers (WCC 17 × 10⁹/L, CRP 185 mg/L). What feature in her presentation most strongly suggests the need for urgent surgical intervention?
A. Duration of conservative management exceeding 48 hours without resolution
B. CT findings of bowel dilatation exceeding 4 cm diameter
C. Persistent tachycardia and rising inflammatory markers despite adequate resuscitation (Correct Answer)
D. History of multiple previous bowel resections increasing surgical risk
E. Presence of thickened bowel wall suggesting active Crohn's inflammation
Explanation: ***Persistent tachycardia and rising inflammatory markers despite adequate resuscitation***- These clinical signs are strongly indicative of **bowel ischemia**, strangulation, or impending perforation, which are absolute indications for **urgent surgical intervention**.- While many Crohn's-related obstructions resolve with conservative care, failure to improve hemodynamically (e.g., **persistent tachycardia**) and worsening **leukocytosis/CRP** suggest the bowel is compromised.*Duration of conservative management exceeding 48 hours without resolution*- Conservative management for small bowel obstruction can often be safely continued for **72 hours** or longer if the patient remains clinically stable.- Duration alone is not a mandate for surgery if the patient is improving; however, **clinical deterioration** overrides any planned observation period.*CT findings of bowel dilatation exceeding 4 cm diameter*- Small bowel dilatation greater than **3 cm** is a diagnostic criterion for obstruction but does not independently dictate the need for immediate surgery.- The **transition point** and secondary signs like **mesenteric stranding** are more important than the absolute diameter when assessing the severity of the obstruction.*History of multiple previous bowel resections increasing surgical risk*- A complex surgical history may actually favor a **conservative approach** initially to avoid further **adhesions** and risks like **Short Bowel Syndrome**.- While this history complicates the patient's condition, it is a reason for caution rather than an indicator for urgent surgery compared to signs of **strangulation**.*Presence of thickened bowel wall suggesting active Crohn's inflammation*- Wall thickening can represent **acute-on-chronic inflammation** which may respond better to **medical management** (e.g., IV corticosteroids) than surgery.- Surgical intervention is reserved for **obstruction non-responsive to medical therapy** or mechanical complications rather than the presence of inflammation alone.
Question 48: A 57-year-old man undergoes emergency laparotomy for perforated sigmoid diverticulitis with faecal peritonitis. At surgery, a 2 cm perforation is found with widespread faecal contamination. His pre-operative observations showed BP 95/60 mmHg, HR 115 bpm, and temperature 38.9°C. Intra-operatively, after washout, what is the most appropriate surgical management according to current evidence-based guidelines?
A. Primary resection with immediate anastomosis and defunctioning loop ileostomy
B. Hartmann's procedure with end colostomy and oversewing of rectal stump (Correct Answer)
C. Simple closure of perforation with omental patch and peritoneal lavage
D. Laparoscopic peritoneal lavage alone without resection
E. Subtotal colectomy with ileorectal anastomosis
Explanation: ***Hartmann's procedure with end colostomy and oversewing of rectal stump***- In a patient with **faecal peritonitis** (Hinchey IV) and **haemodynamic instability** (BP 95/60 mmHg, HR 115 bpm), Hartmann's procedure is the safest, most widely accepted management.- This approach prioritizes **source control** by resecting the perforated segment and avoids a high-risk anastomosis in a **contaminated peritoneal field**, thereby improving patient survival.*Primary resection with immediate anastomosis and defunctioning loop ileostomy*- While this technique is considered in some Hinchey III (purulent peritonitis) cases, it is generally contraindicated in cases of **faecal peritonitis** and **septic shock** due to a significantly elevated risk of anastomotic leak.- The patient's **hemodynamic compromise** and widespread faecal contamination make a primary anastomosis unsafe according to current evidence-based guidelines.*Simple closure of perforation with omental patch and peritoneal lavage*- Simple closure is inappropriate for **sigmoid diverticular perforations** because the underlying diseased bowel remains in situ, posing a high risk for persistent sepsis and re-perforation.- Unlike peptic ulcer perforations, colonic perforations in the setting of diverticulitis typically require **segmental resection** of the diseased bowel to achieve definitive source control.*Laparoscopic peritoneal lavage alone without resection*- Clinical trials have shown that lavage alone is associated with higher rates of **re-intervention** and persistent sepsis compared to resection in cases of perforated diverticulitis.- This management is specifically discouraged in **Hinchey IV disease**, where gross faecal contamination necessitates the removal of the perforated segment for effective source control.*Subtotal colectomy with ileorectal anastomosis*- This procedure is overly extensive for localized sigmoid diverticulitis and is typically reserved for diffuse colonic diseases, such as **toxic megacolon** or certain cases of extensive inflammatory bowel disease or **synchronous colon cancers**.- Performing such a major anastomosis in the presence of **peritonitis** and **hypotension** significantly increases the risk of life-threatening anastomotic failure and is not indicated for this presentation.
Question 49: A 68-year-old man with atrial fibrillation presents with a 6-hour history of sudden onset severe generalized abdominal pain that is disproportionate to examination findings. He passed one episode of bloody diarrhoea. His pulse is irregularly irregular at 98 bpm. Abdominal examination reveals mild diffuse tenderness without guarding. Blood tests show WCC 16.5 × 10⁹/L, lactate 4.8 mmol/L, and metabolic acidosis on VBG. What CT finding would most specifically confirm the suspected diagnosis?
A. Pneumatosis intestinalis with gas in the portal venous system
B. Thickened bowel wall with absent mucosal enhancement and surrounding fat stranding (Correct Answer)
C. Superior mesenteric artery filling defect with occluded distal branches
D. Free intraperitoneal air under the diaphragm
E. Dilated fluid-filled loops of small bowel with transition point
Explanation: ***Thickened bowel wall with absent mucosal enhancement and surrounding fat stranding***
- **Acute mesenteric ischemia** presents with **pain disproportionate to examination findings** and a **high lactate**, and **absent mucosal enhancement** on CT is a highly specific sign of compromised tissue perfusion.
- These findings indicate that the **bowel wall** is no longer receiving adequate blood flow, confirming active ischemia and often necessitating urgent surgical intervention.
*Pneumatosis intestinalis with gas in the portal venous system*
- This finding indicates **transmural bowel infarction** and necrosis, but it is typically a **late sign** rather than an early confirmatory finding of acute ischemia.
- While specific for necrosis, it often suggests that the bowel is already **irreversibly damaged** or gangrenous, rather than just ischemic.
*Superior mesenteric artery filling defect with occluded distal branches*
- This identifies the **embolic source** (common in atrial fibrillation) but does not definitively confirm if the **intestinal tissue** is currently ischemic or infarcted.
- Collateral circulation may prevent ischemia even in the presence of an **arterial occlusion**, making this finding less specific for bowel viability than the enhancement pattern.
*Free intraperitoneal air under the diaphragm*
- This is a sign of **hollow viscus perforation**, which can be a terminal complication of mesenteric ischemia but is not specific to the ischemia itself.
- It indicates a **surgical emergency** (peritonitis) but does not directly confirm the vascular status of the remaining bowel or the presence of ischemia.
*Dilated fluid-filled loops of small bowel with transition point*
- These are characteristic signs of a **mechanical small bowel obstruction**, which can present with similar pain but has a different underlying pathophysiology.
- While severe ischemia can lead to a **paralytic ileus**, a clear **transition point** points toward an extrinsic or intrinsic mechanical blockage rather than primary **vascular compromise**.
Question 50: A 63-year-old man with metastatic colorectal cancer on palliative chemotherapy presents with a 4-day history of colicky abdominal pain, distension, and vomiting. He has not opened his bowels for 5 days. CT imaging shows dilated small bowel loops up to 4 cm with a transition point at the terminal ileum where there is peritoneal disease. Conservative management with IV fluids and nasogastric decompression is commenced. After 48 hours, his symptoms partially improve but obstruction persists. What is the most appropriate next intervention?
A. Continue conservative management for a further 72 hours
B. Emergency laparotomy with bowel resection
C. Trial of water-soluble contrast (Gastrografin) with serial imaging (Correct Answer)
D. Insertion of a decompressing gastrostomy tube
E. Endoscopic placement of an enteral stent
Explanation: ***Trial of water-soluble contrast (Gastrografin) with serial imaging***
- **Gastrografin** is both diagnostic and therapeutic; its **hyperosmolar** nature draws fluid into the bowel lumen, reducing wall edema and stimulating perstalsis.
- If contrast reaches the colon within **24 hours**, it is a strong predictor of successful resolution of the **small bowel obstruction** without the need for surgical intervention.
*Continue conservative management for a further 72 hours*
- Waiting an additional 72 hours without progress or intervention increases the risk of **bowel ischemia** or perforation in a patient with **persistent obstruction**.
- Standard protocols recommend assessing the efficacy of conservative management within **48 to 72 hours**; clinical stagnation necessitates a change in strategy.
*Emergency laparotomy with bowel resection*
- Surgery in the setting of **metastatic peritoneal disease** carries high **morbidity and mortality** rates and should be avoided if possible.
- A laparotomy is generally reserved for patients with signs of **strangulation**, ischemia, or those who fail less invasive therapeutic trials.
*Insertion of a decompressing gastrostomy tube*
- A **venting gastrostomy** is primarily a palliative measure for symptomatic relief of vomiting when the obstruction is irreversible.
- It does not attempt to resolve the **mechanical obstruction** itself and is typically used later in the management algorithm for patients with **end-stage malignancy**.
*Endoscopic placement of an enteral stent*
- **Self-expanding metal stents (SEMS)** are highly effective for **large bowel obstructions** but are technically challenging for small bowel sites like the **terminal ileum**.
- Stenting is often unsuccessful in cases of **peritoneal carcinomatosis** because there are frequently multiple levels of obstruction rather than a single focal point.
