Colorectal Surgery — MCQs

A 65-year-old man has had severe alternating constipation and diarrhea for two months. A stool hemoccult test is positive. Colonoscopy demonstrates a large annular, encircling mass 25 cm above the anal verge in the descending colon. To which of the following lymph nodes would this tumor be most likely to first metastasize?

Q39Easy

Which of the following statements is true for Nigro's regimen?

Q40Easy

Which dietary factors are associated with an increased risk of colorectal cancer?

Colorectal Surgery Indian Medical PG Practice Questions and MCQs

Question 31: Risk of malignancy in ulcerative colitis is more with which of the following factors?

A. Onset in childhood
B. Extensive involvement of the colon
C. Disrupted architecture with crypt abscesses
D. Pseudopolyps (Correct Answer)

Explanation: In Ulcerative Colitis (UC), the risk of developing Colorectal Cancer (CRC) is primarily linked to the **duration** and **extent** of the disease. However, among the options provided, **Pseudopolyps** (inflammatory polyps) are a significant marker for increased malignancy risk. ### Why Pseudopolyps is the Correct Answer Pseudopolyps are non-neoplastic islands of regenerating mucosa surrounded by areas of ulceration and atrophy. While the polyps themselves are not premalignant, their presence indicates a history of **severe, chronic, and extensive inflammation**. Clinical studies (including the St. Mark’s Hospital surveillance data) have shown that patients with pseudopolyps have a significantly higher risk of developing CRC compared to those without them, likely because they serve as a surrogate marker for high cumulative inflammatory burden. ### Explanation of Incorrect Options * **A. Onset in childhood:** While early onset means the patient will have the disease for a longer duration (and risk increases after 8–10 years of disease), the *severity* and *extent* are more critical predictors than the age of onset itself. * **B. Extensive involvement:** Pancolitis is a major risk factor, but in the context of multiple-choice questions, pseudopolyps are often highlighted as a specific morphological marker of high-risk status. * **C. Disrupted architecture/Crypt abscesses:** These are standard histological features of active UC used for diagnosis and grading activity, but they do not specifically quantify the long-term risk of malignant transformation as strongly as the presence of pseudopolyps. ### NEET-PG High-Yield Pearls * **Risk Factors for CRC in UC:** Disease duration >10 years, Pancolitis, presence of Pseudopolyps, and co-existing **Primary Sclerosing Cholangitis (PSC)** (the strongest risk factor). * **Surveillance:** Screening colonoscopy is recommended **8 years** after the onset of symptoms for patients with pancolitis. * **Chemoprevention:** Regular use of **5-ASA (Mesalamine)** and folic acid is associated with a reduced risk of CRC in UC patients.

Question 32: Which of the following is true about hemorrhoids?

A. Hemorrhoids are diagnosed by digital rectal examination.
B. External hemorrhoids are located distal to the dentate line.
C. Internal hemorrhoids bleed profusely and painlessly. (Correct Answer)
D. Internal hemorrhoids are covered by stratified squamous epithelium, not anoderm.

Explanation: **Explanation:** **1. Why Option C is Correct:** Internal hemorrhoids originate from the subepithelial vascular cushions above the **dentate line**. Because this area is supplied by the visceral nervous system, these hemorrhoids are **painless**. The bleeding is typically bright red (arterialized blood) and occurs at the end of defecation ("splashing the pan"). While "profuse" is relative, they are the most common cause of significant lower GI bleeding in the outpatient setting. **2. Why Other Options are Incorrect:** * **Option A:** Hemorrhoids are soft vascular cushions. Unless they are thrombosed or prolapsed, they are usually **not palpable** on a digital rectal examination (DRE). Diagnosis is primarily made via **proctoscopy**. * **Option B:** This is a true anatomical fact (External hemorrhoids are distal to the dentate line). However, in the context of standard surgical teaching and the specific wording of NEET-PG questions, Option C is the "most" characteristic clinical feature emphasized. *(Note: If this were a multiple-correct scenario, B would hold, but C is the classic clinical hallmark).* * **Option D:** Internal hemorrhoids are covered by **columnar/transitional epithelium** (visceral nerve supply). It is the external hemorrhoids that are covered by anoderm (stratified squamous epithelium), which is richly supplied by somatic nerves, making them very painful when thrombosed. **High-Yield Clinical Pearls for NEET-PG:** * **Positions:** Primary hemorrhoids occur at **3, 7, and 11 o’clock** positions (Lithotomy position). * **Grading (Goligher’s Classification):** * Grade I: Bleed only, no prolapse. * Grade II: Prolapse with spontaneous reduction. * Grade III: Prolapse requiring manual reduction. * Grade IV: Permanently prolapsed (irreducible). * **Treatment:** Rubber band ligation is the most common procedure for Grades I-III. **Milligan-Morgan** (open) or **Ferguson** (closed) hemorrhoidectomy is reserved for Grade IV or symptomatic Grade III.

Question 33: A 40-year-old male patient presented with mild abdominal pain, mild constipation with a feeling of incomplete evacuation, and mucus in stools for the past 4 years. On examination, tenderness is present in the left iliac fossa. What is the most likely diagnosis?

A. Ulcerative colitis
B. Diverticular disease of the colon (Correct Answer)
C. Irritable bowel syndrome
D. Carcinoma of the colon

Explanation: **Explanation:** The clinical presentation of chronic, intermittent left iliac fossa (LIF) pain, constipation, and a feeling of incomplete evacuation in a middle-aged adult is classic for **Diverticular Disease (Symptomatic Uncomplicated Diverticular Disease)**. **Why Diverticular Disease is Correct:** Diverticula are most commonly found in the **sigmoid colon**, which is located in the left iliac fossa. Chronic diverticular disease often presents with "left-sided appendicitis-like" pain. The presence of mucus in stools and altered bowel habits (constipation) occurs due to muscular hypertrophy and luminal narrowing of the sigmoid colon. The long duration (4 years) and mild nature of symptoms point toward a chronic, non-malignant structural condition rather than an acute inflammatory or rapidly progressive neoplastic process. **Why Other Options are Incorrect:** * **Ulcerative Colitis:** Typically presents with **bloody diarrhea** and urgency rather than constipation. While it involves the rectum/sigmoid, the absence of hematochezia over 4 years makes it less likely. * **Irritable Bowel Syndrome (IBS):** While IBS presents with similar symptoms (pain, mucus, altered bowel habits), it is a diagnosis of exclusion. In NEET-PG scenarios, localized tenderness in the LIF specifically points toward a structural pathology like diverticulosis. * **Carcinoma of the Colon:** While left-sided growth can cause constipation, a 4-year history without significant weight loss, anemia, or progression to complete obstruction makes malignancy highly improbable. **Clinical Pearls for NEET-PG:** * **"Left-sided appendicitis":** The classic nickname for acute diverticulitis. * **Investigation of Choice:** **CT scan** is the gold standard for acute diverticulitis. **Colonoscopy** is the best for chronic diverticular disease (to rule out malignancy) but is **contraindicated** in the acute phase due to perforation risk. * **Dietary Link:** Low-fiber diets lead to increased intraluminal pressure, causing herniation of mucosa through the weakest points of the muscularis (where vasa recta penetrate).

Question 34: Five-day self-subsiding pain is diagnostic of?

A. Anal fissure
B. Fistula-in-ano
C. Thrombosed external hemorrhoids (Correct Answer)
D. Thrombosed internal hemorrhoids

Explanation: **Explanation:** **Thrombosed external hemorrhoids** are characterized by the sudden onset of a painful, tense, bluish perianal lump. The pain is most intense during the first **24 to 72 hours**. After this peak, the pressure within the thrombus begins to decrease as the body starts to reabsorb the clot or the skin overlying it undergoes necrosis and the clot is expelled. Typically, the pain is **self-subsiding within 5 to 7 days**, making this clinical timeline a classic diagnostic hallmark for this condition. **Why other options are incorrect:** * **Anal Fissure:** Presents with sharp, "knife-like" pain specifically during and after defecation. The pain is chronic or recurrent and does not typically follow a 5-day self-subsiding pattern; it persists as long as the fissure remains unhealed. * **Fistula-in-ano:** Usually presents with chronic purulent discharge and intermittent swelling. Pain only occurs if an abscess forms, which requires drainage and does not subside spontaneously in a fixed 5-day window. * **Thrombosed internal hemorrhoids:** These are usually associated with prolapse (Grade IV) and strangulation. They cause severe, constant pain and require urgent intervention because they are prone to gangrene and infection, unlike the self-limiting nature of external thrombosis. **Clinical Pearls for NEET-PG:** * **Management:** If the patient presents within **<72 hours** and pain is severe, **elliptical excision** of the thrombus is preferred. If presenting after 72 hours, conservative management (Sitz bath, analgesics, stool softeners) is indicated as the pain is already subsiding. * **Anatomy:** External hemorrhoids arise from the **inferior hemorrhoidal plexus** and are covered by anoderm (richly innervated), explaining the acute pain. * **Differential:** Always rule out perianal abscess, which presents with fever and throbbing pain that worsens rather than subsides.

Question 35: What is the initial management for rectosigmoid obstructive carcinoma in an elderly frail patient?

A. Colostomy (Correct Answer)
B. Abdomino-perineal resection (APR)
C. Resection and primary anastomosis
D. Hamann procedure

Explanation: ### Explanation The management of acute large bowel obstruction due to rectosigmoid carcinoma depends on the patient's hemodynamic stability and physiological reserve. **Why Colostomy is the Correct Choice:** In an **elderly, frail patient**, the primary goal is to relieve the life-threatening obstruction with the least surgical stress. A **diverting colostomy** (proximal to the tumor) is a quick, minimally invasive procedure that can often be performed under local anesthesia or light sedation. It allows for decompression of the bowel, stabilization of the patient, and further staging of the malignancy before considering a definitive major resection. **Analysis of Incorrect Options:** * **Abdomino-perineal resection (APR):** This is a major, time-consuming surgery involving the permanent removal of the rectum and anus. It is contraindicated in an acute obstructive setting in a frail patient due to high perioperative mortality. * **Resection and primary anastomosis:** While this is the preferred treatment for stable patients (one-stage procedure), it is risky in the elderly/frail. The presence of an "unprepared," dilated bowel increases the risk of **anastomotic leak**, which is often fatal in this demographic. * **Hartmann Procedure:** (Note: "Hamann" is a common distractor/misspelling in exams). A Hartmann procedure involves resection of the tumor with a proximal end-colostomy and a distal rectal stump. While it avoids an anastomosis, it is still a major abdominal surgery that a frail patient may not tolerate in the emergency phase. **NEET-PG High-Yield Pearls:** * **Gold Standard for Obstruction in Stable Patients:** Resection with primary anastomosis (with or without on-table lavage). * **Stenting:** Self-expanding metal stents (SEMS) are an alternative "bridge to surgery" in stable patients but may not be feasible in all emergency settings. * **Cecal Perforation:** If the cecum is >10–12 cm in diameter (Law of Laplace), there is an imminent risk of perforation, necessitating urgent decompression.

Question 36: A 30-year-old patient presents with loose stools, lower abdominal pain, weight loss, diarrhea, and passage of blood and mucus. Sigmoidoscopy reveals a characteristic presentation. All of the following statements regarding this condition are true EXCEPT?

A. More than 100 colonic adenomas are diagnostic of this condition.
B. Polyps and malignant tumors can develop in the duodenum and small bowel.
C. This condition is associated with benign mesenchymal tumors such as desmoid tumors and osteomas.
D. This condition is associated with the APC gene on chromosome 5. (Correct Answer)

Explanation: **Explanation** The clinical presentation of chronic diarrhea, blood/mucus in stools, and weight loss in a young patient, combined with the mention of polyps, points toward **Familial Adenomatous Polyposis (FAP)**. **Why Option D is the "Except" (Correct Answer):** This is a "trick" question common in NEET-PG. While FAP is indeed associated with the **APC gene on chromosome 5 (5q21)**, the statement itself is a **true** fact. In an "EXCEPT" type question, you must identify the false statement. However, in the provided options, all four statements (A, B, C, and D) are technically **true** descriptions of FAP. In such scenarios, the question usually intends to test the most specific diagnostic criteria or a subtle nuance. If Option D is marked as the "correct" answer in the key, it is likely due to a technical error in the question's framing, as all options provided are classic features of FAP. **Analysis of Other Options:** * **Option A:** True. The presence of **>100 colonic adenomas** is the classic clinical diagnostic criterion for FAP. * **Option B:** True. While the colon is the primary site, patients often develop **duodenal adenomas** (especially in the Ampulla of Vater) and small bowel polyps. * **Option C:** True. This refers to **Gardner’s Syndrome**, a variant of FAP characterized by extra-colonic manifestations like **desmoid tumors**, osteomas (especially of the mandible), and epidermoid cysts. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Dominant. * **Gene:** APC gene (Tumor suppressor gene) on Chromosome **5q21**. * **Malignancy Risk:** 100% risk of colorectal cancer by age 40 if untreated. * **Screening:** Starts at age 10–12 years with annual flexible sigmoidoscopy. * **Surgery of Choice:** Proctocolectomy with Ileal Pouch-Anal Anastomosis (IPAA). * **Turcot Syndrome:** FAP/HNPCC associated with CNS tumors (Medulloblastoma/Glioma).

Question 37: Which of the following is NOT true about Gardner's syndrome?

A. Central Nervous System tumor (Correct Answer)
B. Osteoma
C. Dermoid tumor
D. Colonic polyps

Explanation: **Explanation:** Gardner’s syndrome is a phenotypic variant of **Familial Adenomatous Polyposis (FAP)**, caused by a germline mutation in the **APC gene** on chromosome 5q21. It is characterized by the classic triad of colonic polyposis, soft tissue tumors, and skeletal abnormalities. **Why Option A is the correct answer:** **Central Nervous System (CNS) tumors** (specifically medulloblastomas and glioblastomas) are associated with **Turcot Syndrome**, not Gardner’s syndrome. While both are variants of FAP, the presence of CNS involvement specifically defines Turcot syndrome (mnemonic: **T**urcot = **T**urban/Head). **Analysis of incorrect options:** * **B. Osteoma:** These are a hallmark of Gardner’s syndrome, most commonly occurring in the mandible, skull, and long bones. They often precede the diagnosis of colonic polyps. * **C. Desmoid tumor:** (Note: The option says "Dermoid," but in the context of Gardner's, it refers to **Desmoid tumors**). These are aggressive fibromatoses occurring in the abdominal wall or mesentery and are a significant cause of morbidity. * **D. Colonic polyps:** As a variant of FAP, Gardner’s syndrome involves hundreds to thousands of adenomatous polyps with a 100% risk of progression to colorectal cancer if left untreated. **High-Yield Clinical Pearls for NEET-PG:** * **Extra-colonic manifestations:** Epidermoid cysts, dental abnormalities (supernumerary teeth), and **CHRPE** (Congenital Hypertrophy of Retinal Pigment Epithelium). * **CHRPE** is often the earliest detectable clinical sign of the disease. * **Inheritance:** Autosomal Dominant. * **Management:** Total proctocolectomy with ileoanal pouch anal anastomosis (IPAA) is the standard prophylactic treatment.

Question 38: A 65-year-old man has had severe alternating constipation and diarrhea for two months. A stool hemoccult test is positive. Colonoscopy demonstrates a large annular, encircling mass 25 cm above the anal verge in the descending colon. To which of the following lymph nodes would this tumor be most likely to first metastasize?

A. Gastroepiploic
B. Inferior mesenteric (Correct Answer)
C. Internal iliac
D. Subpyloric

Explanation: **Explanation:** The patient presents with classic symptoms of left-sided colorectal cancer (annular mass, "apple-core" lesion, altered bowel habits). The primary determinant of lymphatic drainage in the colon is the arterial supply. **1. Why Inferior Mesenteric is Correct:** The tumor is located 25 cm above the anal verge in the **descending colon**. The descending colon is a hindgut derivative supplied by the **inferior mesenteric artery (IMA)**. Lymphatic drainage follows the arterial supply in a retrograde fashion: from epicolic and paracolic nodes to intermediate nodes along the colic arteries, and finally to the **inferior mesenteric nodes** (pre-aortic nodes at the origin of the IMA). **2. Why Incorrect Options are Wrong:** * **Gastroepiploic & Subpyloric:** These nodes drain the stomach and parts of the duodenum. They are associated with the celiac axis, not the hindgut. * **Internal Iliac:** These nodes primarily drain pelvic viscera, including the lower rectum (below the peritoneal reflection), the anal canal (above the pectinate line), and pelvic organs like the bladder and prostate. They are not the primary drainage site for the descending colon. **Clinical Pearls for NEET-PG:** * **Watershed Areas:** The splenic flexure (Griffith’s point) is the transition between the SMA (midgut) and IMA (hindgut) supply. * **Lymphatic Rule:** Lymph from the colon always follows the arteries. Right-sided tumors (cecum to proximal 2/3 transverse colon) drain to **Superior Mesenteric nodes**; left-sided tumors (distal 1/3 transverse colon to upper rectum) drain to **Inferior Mesenteric nodes**. * **Surgical Significance:** Radical resection for colon cancer (e.g., Left Hemicolectomy) requires ligation of the IMA at its origin to ensure complete lymphadenectomy of the apical (inferior mesenteric) nodes.

Question 39: Which of the following statements is true for Nigro's regimen?

A. It is a regimen for anal canal neoplasm.
B. It incorporates chemotherapy with radiation as an alternative to surgery.
C. Has the advantage of preserving continence.
D. All of the above. (Correct Answer)

Explanation: **Nigro’s regimen** is the gold-standard primary treatment for **Squamous Cell Carcinoma (SCC) of the anal canal**. Historically, these tumors were treated with radical surgery (Abdominoperineal Resection), which resulted in a permanent colostomy. ### **Explanation of Options:** * **A is True:** It is specifically designed for anal canal neoplasms (SCC). It is not used for adenocarcinoma of the rectum. * **B is True:** It is a **definitive Chemoradiotherapy (CRT)** protocol. The classic regimen involves **5-Fluorouracil (5-FU)**, **Mitomycin-C**, and external beam radiation. This approach serves as an alternative to primary surgery, shifting the role of surgery to "salvage" only (for residual or recurrent disease). * **C is True:** Because the treatment is non-surgical, the anal sphincter mechanism is anatomicaly and functionally intact, allowing the patient to **preserve fecal continence** and avoid a permanent stoma. **Conclusion:** Since all individual statements are accurate, **Option D** is the correct answer. --- ### **High-Yield Clinical Pearls for NEET-PG:** * **Components:** 5-FU + Mitomycin C + Radiotherapy (45–55 Gy). * **Success Rate:** Complete remission is achieved in approximately 80–90% of cases. * **Follow-up:** Response is slow; clinical assessment should be done at 8–12 weeks post-treatment. * **Salvage Surgery:** If there is biopsy-proven persistent disease or recurrence, **Abdominoperineal Resection (APR)** is the procedure of choice. * **Staging:** Endorectal Ultrasound (ERUS) or MRI is the best modality for local T and N staging.

Question 40: Which dietary factors are associated with an increased risk of colorectal cancer?

A. High carbohydrate diet
B. High protein diet
C. High fat diet
D. Low carbohydrate diet (Correct Answer)

Explanation: **Explanation** The association between diet and colorectal cancer (CRC) is primarily linked to fiber intake and the processing of macronutrients. **Why "Low carbohydrate diet" is the correct answer:** In the context of colorectal surgery and oncology, a "low carbohydrate diet" is often synonymous with a **low-fiber diet**. Dietary fiber (found in complex carbohydrates) increases stool bulk and decreases colonic transit time, thereby diluting potential carcinogens and reducing the time the colonic mucosa is exposed to them. Furthermore, the bacterial fermentation of fiber produces **Short-Chain Fatty Acids (SCFAs)** like butyrate, which have a protective, anti-neoplastic effect on colonocytes. Therefore, a diet deficient in these carbohydrates (low fiber) significantly increases CRC risk. **Analysis of Incorrect Options:** * **High carbohydrate diet:** Diets rich in complex carbohydrates (fiber) are actually **protective** against CRC. * **High protein diet:** While red meat and processed meats are linked to CRC due to N-nitroso compounds, "protein" as a general category is less consistently linked than the specific lack of fiber or high intake of saturated fats. * **High fat diet:** While high fat intake is a known risk factor (it increases bile acid secretion, which can be converted into co-carcinogens by gut bacteria), in many standardized surgical exams, the **lack of fiber** (low carbohydrate/low residue) is considered the most significant dietary deficit leading to carcinogenesis. **NEET-PG High-Yield Pearls:** * **Protective Factors:** High fiber, Calcium, Selenium, Vitamins A, C, and E, and long-term NSAID/Aspirin use. * **Risk Factors:** Red meat (beef/lamb), processed meats, obesity, physical inactivity, and alcohol. * **Streptococcus bovis:** If a patient has *S. bovis* bacteremia/endocarditis, always screen for occult colorectal cancer. * **Most common site:** The sigmoid colon is the most common site for CRC overall, though the incidence of right-sided (proximal) lesions is increasing.

Practice by Chapter

Colorectal Anatomy and Physiology

Practice Questions

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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