Colorectal Surgery — MCQs

Colorectal Surgery Indian Medical PG Practice Questions and MCQs

Question 201: A 65-year-old man presents with intermittent constipation and microcytic anemia. Barium enema shows a non-obstructing "apple-core" lesion in the proximal sigmoid colon. Colonoscopy confirms the mass and finds no synchronous lesions. What is the most appropriate next step in management?

A. Left hemicolectomy (Correct Answer)
B. Right hemicolectomy
C. Subtotal colectomy
D. Total colectomy

Explanation: ### Explanation **1. Why Left Hemicolectomy is the Correct Answer:** The patient presents with a classic "apple-core" lesion (annular constricting carcinoma) in the **proximal sigmoid colon**. For malignancies located in the distal descending colon or sigmoid colon, the standard oncological procedure is a **Left Hemicolectomy**. * **Extent of Resection:** This involves ligating the **Inferior Mesenteric Artery (IMA)** at its origin to ensure adequate lymphadenectomy. * **Anastomosis:** The resection encompasses the distal transverse colon, descending colon, and sigmoid colon, followed by an anastomosis between the transverse colon and the upper rectum. **2. Why Other Options are Incorrect:** * **B. Right Hemicolectomy:** This is indicated for tumors of the cecum, ascending colon, or hepatic flexure. It involves ligating the ileocolic and right colic arteries. * **C & D. Subtotal/Total Colectomy:** These extensive procedures are reserved for patients with **synchronous lesions** (multiple primary tumors), hereditary syndromes (like FAP or Lynch syndrome), or emergency presentations of obstructing left-sided colon cancer with a dilated, thinned-out cecum (impending perforation). Since colonoscopy confirmed no synchronous lesions, these are unnecessary. **3. Clinical Pearls for NEET-PG:** * **Apple-core lesion:** Highly suggestive of malignancy; it represents circumferential growth with mucosal destruction. * **Microcytic Anemia:** While more common in right-sided (caecal) cancers due to occult bleeding, it can occur in any colonic malignancy. * **Resection Margins:** A minimum of **5 cm proximal and distal** longitudinal margins is required for colon cancer, along with the removal of at least **12 lymph nodes** for accurate staging. * **Blood Supply:** The sigmoid colon is primarily supplied by sigmoid branches of the IMA. A left hemicolectomy ensures the removal of the entire lymphatic drainage basin associated with this vessel.

Question 202: Full bowel preparation is avoided in all, except:

A. Carcinoma colon (Correct Answer)
B. Hirschsprung's disease
C. Ulcerative colitis
D. Irritable bowel syndrome

Explanation: **Explanation:** The core concept behind this question is the safety and necessity of mechanical bowel preparation (MBP) versus the risk of complications like perforation or toxic megacolon. **1. Why Carcinoma Colon is Correct:** In elective colorectal surgeries for **Carcinoma Colon**, full bowel preparation (using polyethylene glycol or sodium phosphate) is traditionally employed to clear the fecal load. This facilitates intraoperative palpation of the tumor, allows for easier handling of the bowel, and is often combined with oral antibiotics to reduce the risk of surgical site infections (SSI). While recent ERAS (Enhanced Recovery After Surgery) protocols debate its absolute necessity, it remains a standard practice for elective colonic resections. **2. Why the other options are wrong:** * **Hirschsprung’s Disease:** Full mechanical preparation is avoided because the aganglionic segment causes a functional obstruction. Aggressive preparation can lead to massive colonic distension, enterocolitis, or perforation. * **Ulcerative Colitis (Acute Phase):** In active or severe colitis, bowel preparation is strictly contraindicated. The inflamed, friable mucosa is highly susceptible to perforation, and the osmotic load of the purgative can precipitate **Toxic Megacolon**. * **Irritable Bowel Syndrome (IBS):** There is no surgical or diagnostic indication for "full bowel preparation" in IBS. Furthermore, the osmotic agents used in MBP can severely exacerbate symptoms like abdominal pain and bloating in IBS patients. **Clinical Pearls for NEET-PG:** * **Toxic Megacolon:** A life-threatening complication of Ulcerative Colitis where MBP and barium enemas are strictly contraindicated. * **Antibiotic Prophylaxis:** Current guidelines suggest that MBP is most effective when combined with **oral non-absorbable antibiotics** (e.g., Neomycin + Erythromycin) to reduce SSI. * **Hirschsprung’s Diagnosis:** The gold standard is a rectal suction biopsy; full bowel prep is never the initial step.

Question 203: What is the management for carcinoma of the sigmoid colon with obstruction?

A. Hamann's procedure (Correct Answer)
B. Resection and end-to-end anastomosis with proximal colostomy
C. Proximal colostomy with distal ligation
D. Sub-total colectomy

Explanation: **Explanation:** The management of an obstructed carcinoma of the sigmoid colon is a classic surgical dilemma. In an emergency setting with a loaded, unprepared bowel, a primary anastomosis carries a high risk of leakage. **1. Why Hartmann’s Procedure is Correct:** Hartmann’s procedure (Option A) involves **resection of the diseased sigmoid segment**, followed by the creation of an **end-colostomy** (proximal) and a **distal rectal stump closure** (or mucous fistula). This is the gold standard for obstructed left-sided cancers because it removes the primary pathology immediately while avoiding the risks of a primary anastomosis in an edematous, fecal-loaded bowel. **2. Analysis of Incorrect Options:** * **Option B:** Resection with primary anastomosis and a "covering" colostomy is generally avoided in emergency obstructions due to the high risk of anastomotic breakdown in an unprepared bowel. * **Option C:** A proximal colostomy without resection (defunctioning) is a palliative measure or the first stage of a multi-stage procedure, but it leaves the tumor in situ, which is not ideal if the patient is fit for resection. * **Option D:** Sub-total colectomy (resection from cecum to sigmoid with ileorectal anastomosis) is an alternative that allows for a safe primary anastomosis (ileum to rectum), but it is a more extensive surgery usually reserved for synchronous tumors or cecal perforation due to closed-loop obstruction. **Clinical Pearls for NEET-PG:** * **Right-sided obstruction:** Usually managed by **Right Hemicolectomy with primary ileocolic anastomosis** (the ileum has a better blood supply and less bacterial load). * **Left-sided obstruction:** **Hartmann’s procedure** is the safest traditional choice. * **On-table Lavage:** If a primary anastomosis is desired on the left side, antegrade colonic lavage must be performed to clear the bowel. * **Stenting:** Self-expanding metal stents (SEMS) are increasingly used as a "bridge to surgery" to convert an emergency case into an elective one.

Question 204: External hemorrhoids, located below the dentate line, are characterized by which of the following?

A. Being painful (Correct Answer)
B. Management involving ligation
C. Absence of skin tags
D. Potential for malignant transformation

Explanation: **Explanation:** The key to understanding hemorrhoids lies in their relationship to the **dentate (pectinate) line**, which serves as a critical anatomical and neurovascular boundary. **1. Why Option A is Correct:** External hemorrhoids originate **below the dentate line** and are covered by **anoderm** (modified squamous epithelium). This area is richly supplied by somatic sensory nerves via the **inferior rectal nerve** (a branch of the pudendal nerve). Consequently, external hemorrhoids—especially when thrombosed—are acutely painful. In contrast, internal hemorrhoids are covered by insensitive visceral mucosa and are typically painless. **2. Why the Other Options are Incorrect:** * **Option B:** Management of external hemorrhoids rarely involves ligation. **Rubber Band Ligation (RBL)** is a standard treatment for Grade II and III *internal* hemorrhoids. Applying a band below the dentate line would cause excruciating somatic pain. * **Option C:** Skin tags (fibroepithelial polyps) are a common sequela of resolved external hemorrhoids. When the edema or thrombus in an external hemorrhoid subsides, the stretched skin often remains as a permanent tag. * **Option D:** Hemorrhoids are vascular cushions consisting of sinusoids, connective tissue, and smooth muscle. They are benign vascular structures and have **no potential for malignant transformation**. **High-Yield Clinical Pearls for NEET-PG:** * **Innervation:** Above dentate line = Autonomic (painless); Below dentate line = Somatic (painful). * **Blood Supply:** Internal hemorrhoids (Superior rectal artery); External hemorrhoids (Inferior rectal artery). * **Primary Positions:** Hemorrhoids typically occur at **3, 7, and 11 o'clock** positions (lithotomy position). * **Treatment of Choice:** For acutely thrombosed external hemorrhoids (within 72 hours), the treatment is **elliptical excision** of the thrombus. For internal hemorrhoids (Grade I/II), it is dietary modification or RBL.

Question 205: Ten years after diagnosis of total proctocolitis, this patient undergoes colonoscopy and biopsy reveals high-grade dysplasia in 2-10 specimens. What should the physician recommend?

A. Repeat colonoscopy in 1 year
B. Increase steroid dosage
C. Early repeat colonoscopy and biopsy of the area
D. Total proctocolectomy (Correct Answer)

Explanation: **Explanation:** This question addresses the management of precancerous lesions in patients with long-standing **Ulcerative Colitis (UC)**. Patients with total proctocolitis (pancolitis) for over 8–10 years are at a significantly increased risk for **Colorectal Cancer (CRC)**. **1. Why Option D is Correct:** In the setting of chronic UC, **High-Grade Dysplasia (HGD)** is a strong predictor of either synchronous or future malignancy. Studies show that approximately 40–50% of UC patients with HGD already have an undetected invasive adenocarcinoma elsewhere in the colon. Because the dysplasia in UC is often multifocal and difficult to visualize endoscopically (unlike sporadic polyps), the standard of care is **Total Proctocolectomy (TPC)**. This procedure is curative for both the underlying UC and the risk of malignancy. **2. Why Other Options are Incorrect:** * **Option A & C:** Surveillance (waiting 1 year) or simply repeating the biopsy is dangerous. Once HGD is confirmed by a gastrointestinal pathologist, the risk of occult cancer is too high to justify delay. * **Option B:** Steroids treat active inflammation (flare-ups) but have no role in treating or reversing cellular dysplasia or preventing cancer. **Clinical Pearls for NEET-PG:** * **Indications for Surgery in UC:** HGD, Low-Grade Dysplasia (LGD) if multifocal or associated with a lesion (DALM), persistent symptoms despite maximal medical therapy, or complications (perforation, toxic megacolon). * **Screening Protocol:** Surveillance colonoscopy should begin **8–10 years** after the diagnosis of pancolitis. * **DALM (Dysplasia Associated Lesion or Mass):** If a dysplastic lesion cannot be completely resected endoscopically, TPC is mandatory. * **Gold Standard Surgery:** Restorative Proctocolectomy with **Ileal Pouch-Anal Anastomosis (IPAA)** is the procedure of choice for most patients.

Question 206: What is a known complication of a stoma (e.g., colostomy)?

A. Prolapse
B. Stenosis
C. Retraction
D. All of the above (Correct Answer)

Explanation: **Explanation:** A stoma is an artificial opening created between a hollow viscus (like the colon or ileus) and the anterior abdominal wall. Because this involves altering the abdominal anatomy and exteriorizing a segment of bowel, it is prone to several mechanical and physiological complications. **Why "All of the Above" is correct:** The correct answer is **D** because prolapse, stenosis, and retraction are all classic, well-documented complications of stoma formation: * **Prolapse (A):** This occurs when a segment of the bowel protrudes excessively through the stoma opening. It is often due to an oversized opening in the abdominal wall or inadequate fixation of the mesentery. * **Stenosis (B):** This is the narrowing of the stoma outlet, often caused by ischemia of the stoma edge, chronic inflammation, or excessive scarring during the healing process. It can lead to obstructive symptoms. * **Retraction (C):** This happens when the stoma sinks below the level of the skin. It is frequently caused by excessive tension on the bowel limb (often in obese patients) or inadequate mobilization of the mesentery. **High-Yield Clinical Pearls for NEET-PG:** * **Parastomal Hernia:** The most common late complication of a stoma. * **Skin Excoriation:** The most common overall complication, especially in ileostomies due to the alkaline nature of small bowel output. * **Ischemia/Necrosis:** The most serious early complication (usually occurs within 24 hours), requiring immediate surgical re-evaluation if the stoma appears dusky or black. * **High-Output Stoma:** Defined as output >1.5–2L/day; it can lead to severe electrolyte imbalances (hypokalemia) and dehydration.

Question 207: All of the following are associated with carcinoma of the colon except?

A. Smoking
B. Alcohol
C. Fibre diet (Correct Answer)
D. Fatty food

Explanation: ### Explanation The correct answer is **C. Fibre diet**. In colorectal surgery and oncology, the relationship between diet and Colorectal Cancer (CRC) is a high-yield topic. A **high-fibre diet** is considered a **protective factor**, not a risk factor, for carcinoma of the colon. #### Why Fibre Diet is the Correct Answer: Dietary fibre reduces the risk of colon cancer through several mechanisms: 1. **Dilution:** It increases stool bulk, thereby diluting potential carcinogens and bile acids in the lumen. 2. **Transit Time:** It speeds up colonic transit, reducing the duration of contact between the mucosa and carcinogens. 3. **Fermentation:** Gut bacteria ferment fibre into **Short-Chain Fatty Acids (SCFAs)** like butyrate, which have anti-inflammatory and anti-neoplastic effects on colonocytes. #### Analysis of Incorrect Options (Risk Factors): * **A. Smoking:** Long-term tobacco use is associated with an increased risk of colorectal adenomas and a higher incidence of CRC, particularly microsatellite unstable (MSI-high) tumors. * **B. Alcohol:** Heavy alcohol consumption is a well-established risk factor. It interferes with folate absorption and its metabolite, acetaldehyde, is a known carcinogen. * **D. Fatty food:** High intake of saturated fats (red meat) increases the secretion of primary bile acids. These are converted by gut bacteria into secondary bile acids (deoxycholic acid), which are promoters of carcinogenesis. #### NEET-PG High-Yield Pearls: * **Most common site of CRC:** Sigmoid colon (historically), though the incidence of right-sided (proximal) colon cancer is increasing. * **Protective agents:** Aspirin/NSAIDs (via COX-2 inhibition), Calcium, Vitamin D, and High-fibre diet. * **Strongest Risk Factor:** Family history/Genetics (FAP, Lynch Syndrome) and Long-standing Ulcerative Colitis. * **Dietary culprit:** Polycyclic aromatic hydrocarbons formed when meat is "charred" or grilled at high temperatures.

Question 208: What is the treatment of choice for chronic ulcerative colitis?

A. Colectomy with ileostomy
B. Colectomy with manual proctectomy and ileoanal pouch anastomosis
C. Proctocolectomy with ileoanal pouch anastomosis (Correct Answer)
D. Ileorectal anastomosis

Explanation: **Explanation:** Ulcerative Colitis (UC) is a mucosal disease that involves the rectum and extends proximally to involve the colon. Because the disease is confined to the mucosa of the large intestine, a **Total Proctocolectomy** is considered curative. **1. Why Option C is Correct:** The gold standard treatment for chronic UC is **Total Proctocolectomy with Ileoanal Pouch Anastomosis (IPAA)**, often referred to as a "J-pouch." This procedure is preferred because it removes the entire diseased organ (colon and rectum) while preserving fecal continence and avoiding a permanent stoma. It eliminates the risk of future colorectal malignancy, which is a significant concern in chronic UC. **2. Why Other Options are Incorrect:** * **Option A:** Colectomy with ileostomy leaves the rectum behind (Proctitis remains), meaning the disease is not cured and the risk of rectal cancer persists. * **Option B:** Manual proctectomy is technically part of the procedure, but "Proctocolectomy" is the standard surgical terminology for the complete removal of both the colon and rectum. * **Option D:** Ileorectal anastomosis (IRA) carries a high risk of recurrence in the retained rectum and is generally avoided unless the rectum is relatively spared and the patient cannot tolerate a pouch. **Clinical Pearls for NEET-PG:** * **Indications for Surgery:** Intractability to medical therapy (most common), toxic megacolon, perforation, and dysplasia/carcinoma. * **Curative Nature:** Surgery is curative for UC but **not** for Crohn’s disease (due to its transmural and skip-lesion nature). * **Pouchitis:** The most common long-term complication after IPAA, typically treated with Metronidazole or Ciprofloxacin. * **Backwash Ileitis:** Seen in 10-20% of patients with pancolitis; it does not contraindicate IPAA.

Question 209: Which of the following best assesses the prognosis for carcinoma of the rectum?

A. Site of the tumor
B. Histological grading (Correct Answer)
C. Size of the tumor
D. Duration of the symptoms

Explanation: **Explanation:** In colorectal malignancies, the prognosis is primarily determined by the biological aggressiveness of the tumor and the extent of its spread. **Why Histological Grading is Correct:** Histological grading (degree of differentiation) is a direct reflection of the tumor's biological behavior. Poorly differentiated (high-grade) tumors or those with signet-ring cells have a significantly higher propensity for lymphovascular invasion and distant metastasis compared to well-differentiated tumors. While the **TNM Staging** (depth of invasion and nodal status) is the single most important clinical predictor of survival, among the options provided, **histological grading** is the most reliable intrinsic indicator of prognosis. **Analysis of Incorrect Options:** * **A. Site of the tumor:** While tumors in the lower third of the rectum may pose surgical challenges (e.g., higher risk of positive circumferential resection margins), the site itself does not dictate the long-term biological prognosis as much as the grade or stage. * **C. Size of the tumor:** In colorectal cancer, the size of the primary lesion does not correlate well with prognosis. A small, high-grade tumor can be more lethal than a large, well-differentiated polypoid mass. * **D. Duration of symptoms:** Symptom duration is subjective and often misleading; many aggressive cancers remain asymptomatic until late stages, while benign conditions may cause symptoms for years. **High-Yield Clinical Pearls for NEET-PG:** * **Dukes’ Staging/TNM Staging:** The most important overall prognostic factor for colorectal cancer. * **CEA (Carcinoembryonic Antigen):** Not used for diagnosis, but the best marker for **monitoring recurrence** and assessing prognosis post-operatively. * **Most common site of metastasis:** Liver (via portal circulation). * **Rectal Cancer specific:** The **Circumferential Resection Margin (CRM)** is the most important predictor of local recurrence after surgery.

Question 210: What is the best investigation for colorectal carcinoma?

A. Exfoliative cytology
B. Air contrast barium enema
C. Ultrasound
D. Colonoscopy and biopsy (Correct Answer)

Explanation: **Explanation:** **Colonoscopy with biopsy** is the gold standard and the investigation of choice for colorectal carcinoma (CRC). Its superiority lies in its ability to provide **direct visualization** of the entire colon (from rectum to cecum) and allow for **tissue diagnosis** via biopsy, which is mandatory for confirming malignancy and planning treatment. It can also detect and remove synchronous polyps, reducing the risk of future cancers. **Why other options are incorrect:** * **Exfoliative cytology:** This involves examining shed cells in the stool. It has very low sensitivity and specificity for diagnosing CRC and is not used in standard clinical practice. * **Air contrast barium enema:** While it can show the "apple-core" deformity (classic for annular growths), it has a high false-negative rate for small lesions and cannot provide a tissue diagnosis. It is now largely replaced by CT Colonography or Colonoscopy. * **Ultrasound:** Transabdominal USG is poor at visualizing hollow viscus organs like the colon. While **Endorectal Ultrasound (ERUS)** is excellent for *staging* the depth of rectal wall invasion (T-staging), it is not the primary diagnostic tool for the cancer itself. **Clinical Pearls for NEET-PG:** * **Screening:** For average-risk individuals, screening starts at **age 45** (updated guidelines). * **Most common site:** Historically the rectum, but there is a shifting trend toward the **proximal (right) colon**. * **Tumor Marker:** **CEA** (Carcinoembryonic Antigen) is used for monitoring recurrence and prognosis, **not** for primary diagnosis or screening. * **Investigation of choice for staging:** Contrast-Enhanced CT (CECT) of the Chest, Abdomen, and Pelvis. For rectal cancer specifically, **MRI Pelvis** is the gold standard for local staging.

Practice by Chapter

Colorectal Anatomy and Physiology

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Diverticular Disease

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Inflammatory Bowel Disease

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Colorectal Polyps

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Colorectal Cancer

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Anorectal Abscess and Fistula

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Hemorrhoids

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Rectal Prolapse

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Fecal Incontinence

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Intestinal Stomas Creation and Management

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Pelvic Floor Disorders

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Enhanced Recovery After Colorectal Surgery

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