Colorectal Surgery Practice Questions

Q: Which type of haemorrhoids is treated by the injection of a sclerosing agent?

Internal haemorrhoids. **Explanation:** **Sclerotherapy** is a non-surgical treatment modality primarily indicated for **early-stage internal haemorrhoids** (specifically 1st degree and early 2nd degree). The procedure involves injecting a sclerosing agent (e.g., 5% Phenol in almond or arachis oil) into the **submucosa** above the dentate line at the base of the pile mass. This induces an inflammatory reaction followed by fibrosis, which obliterates the vascular channels and "pins" the mucosa back to the underlying muscle, preventing prolapse and bleeding. **Analysis of Options:** * **Internal Haemorrhoids (Correct):** These originate above the dentate line and are covered by autonomic-innervated insensitive mucosa. This allows for painless injection. * **External Haemorrhoids (Incorrect):** These are covered by anoderm/skin, which is richly supplied by somatic nerves. Injection here would cause excruciating pain and is contraindicated. * **Prolapsed Haemorrhoids (Incorrect):** 3rd and 4th-degree haemorrhoids generally require mechanical intervention like Rubber Band Ligation (RBL) or surgical haemorrhoidectomy, as sclerotherapy is ineffective for significantly displaced tissue. * **Thrombosed Haemorrhoids (Incorrect):** These are acutely painful emergencies (usually external) requiring incision and evacuation of the clot or conservative management; sclerotherapy has no role in treating a thrombus. **NEET-PG High-Yield Pearls:** * **Site of Injection:** The injection is given at the **pedicle** (3, 7, and 11 o'clock positions) above the dentate line. * **Agent of Choice:** 5% Phenol in oil is most common. * **Complications:** Prostatitis or prostatic abscess (if injected too deeply/anteriorly) and mucosal ulceration (if injected too superficially). * **Contraindication:** Sclerotherapy should never be used for external piles due to the somatic nerve supply.

Q: In a 27-year-old male, what is the most common cause of a colo-vesical fistula?

Crohn's disease. **Explanation:** The correct answer is **Crohn’s disease (Option A)**. A colo-vesical fistula is an abnormal communication between the colon and the urinary bladder. While **Diverticulitis** is the most common cause of colo-vesical fistulae in the **general population** (typically older adults), the question specifies a **27-year-old male**. In younger patients, Crohn’s disease is the leading cause due to its transmural nature, which leads to deep ulcerations, abscess formation, and subsequent fistula tracts. **Analysis of Options:** * **Crohn’s Disease (A):** Correct. It is characterized by transmural inflammation. In young adults, ileovesical or colovesical fistulae are common complications of terminal ileal or sigmoid involvement. * **Ulcerative Colitis (B):** Incorrect. UC is a mucosal disease and does not typically involve the full thickness of the bowel wall; therefore, fistula formation is extremely rare. * **Tuberculosis (C):** Incorrect. While intestinal TB can cause strictures and perforations, it is a less common cause of fistulization to the bladder compared to Crohn's. * **Colon Cancer (D):** Incorrect. Malignancy is the third most common cause overall (after diverticulitis and Crohn's), but it typically presents in older age groups. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Presentation:** Pneumaturia (air in urine), fecaluria (feces in urine), and recurrent UTIs with polymicrobial flora. * **Most Common Site:** Between the sigmoid colon and the dome of the bladder. * **Diagnostic Gold Standard:** **CT Scan with oral/rectal contrast** (shows air in the bladder or contrast entering the bladder). * **The "Bourne Test":** Historically used to detect charcoal in urine after oral administration to confirm a fistula. * **Cystoscopy:** Often shows "bullous edema" at the site of the fistula but rarely visualizes the actual opening.

Q: A 56-year-old man presents with a several-week history of intermittent bright red bloody bowel movements. The blood coats the outside of the stools and is visible in the toilet bowl and on toilet paper. He reports constipation for the past two months and a change in stool caliber to pencil-thin. He denies pain. What is the most likely diagnosis?

Cancer of the rectum. **Explanation:** The clinical presentation of **painless bright red rectal bleeding (hematochezia)** associated with a **change in bowel habits** and **pencil-thin stools** in an older patient is a classic "red flag" for **Rectal Cancer**. 1. **Why Option C is Correct:** Rectal cancers are located distally; therefore, blood does not mix with the stool but rather coats its surface. As the tumor grows circumferentially, it narrows the rectal lumen, leading to the characteristic "pencil-thin" stools (stenosing lesion). Constipation arises from the progressive mechanical obstruction of the distal passage. 2. **Why Other Options are Incorrect:** * **Anal Fissure:** While it causes bright red blood on toilet paper, it is characterized by **exquisite pain** during defecation ("passing shards of glass"), which this patient denies. * **Cancer of the Cecum:** Right-sided colonic cancers typically present with **iron deficiency anemia** and occult bleeding. Because the stool is liquid in the cecum and the lumen is wide, they rarely cause obstruction or visible bright red blood coating the stool. * **External Hemorrhoids:** These usually present as a painful perianal lump (if thrombosed) or itching. While they can bleed, they do not explain the change in stool caliber or persistent constipation. **NEET-PG High-Yield Pearls:** * **Left-sided colon cancer:** Presents with obstruction, change in bowel habits, and "apple-core" lesions on barium enema. * **Right-sided colon cancer:** Presents with anemia, weight loss, and a palpable mass in the right iliac fossa. * **Digital Rectal Examination (DRE):** The most important initial bedside investigation; it can detect up to 40% of colorectal cancers. * **Gold Standard Investigation:** Colonoscopy with biopsy.

Q: In which of the following conditions, local excision in rectal carcinoma cannot be performed?

T1 and T2 cancer with lymph node involvement. ### Explanation Local excision (such as Transanal Endoscopic Microsurgery - TEMS) is a sphincter-preserving approach reserved for **early-stage rectal cancers** where the risk of lymph node metastasis is minimal. **1. Why Option D is Correct:** The primary prerequisite for local excision is the **absence of lymphadenopathy**. Even if a tumor is T1 or T2 (limited to the submucosa or muscularis propria), the presence of lymph node involvement (N1 or N2) automatically upgrades the stage to **Stage III**. Local excision only removes the primary tumor and does not address the mesorectal lymph nodes. Therefore, radical surgery (like APR or LAR) with Total Mesorectal Excision (TME) is mandatory to ensure oncological clearance. **2. Analysis of Incorrect Options:** * **Option A:** Local excision is typically feasible for lesions located within **6–10 cm** of the anal verge (dentate line) because they are accessible transanally. * **Option B:** To be eligible for local excision, the tumor diameter should generally be **less than 3 cm**. A 2.7 cm lesion meets this criterion. * **Option C:** The tumor should occupy **less than 30% to 40%** of the rectal circumference to ensure the defect can be closed without causing stricture. **3. NEET-PG High-Yield Pearls:** * **Ideal Candidate for Local Excision:** T1 lesion, well-to-moderately differentiated, <3 cm size, involving <30% circumference, and no lymphadenopathy on MRI/EUS. * **T2 Lesions:** While some protocols allow local excision for T2, it is controversial due to a higher recurrence rate compared to T1. * **Gold Standard Investigation:** **Pelvic MRI** is the investigation of choice for T-staging and identifying suspicious lymph nodes in rectal cancer. * **Distance from Anal Verge:** Lesions in the distal 1/3rd of the rectum are the primary candidates for local techniques to avoid the morbidity of a permanent colostomy (APR).

Q: Rectal polyps most commonly present as which of the following?

Bleeding. **Explanation:** The most common clinical presentation of rectal polyps is **painless rectal bleeding (hematochezia)**. Polyps are protrusions from the mucosal surface into the lumen; as fecal matter passes through the rectum, it causes mechanical trauma and friction against the fragile, vascularized surface of the polyp, leading to streaky or bright red bleeding. **Analysis of Options:** * **B. Bleeding (Correct):** This is the hallmark symptom. While many polyps are asymptomatic and discovered during screening, bleeding is the most frequent reason a patient seeks medical attention. * **A. Obstruction:** This is rare for rectal polyps. Obstruction typically occurs with very large, circumferential malignant masses or in the narrower segments of the colon (like the sigmoid). Rectal polyps are usually too small to occlude the wide rectal ampulla. * **C. Infection:** Polyps are not primarily infectious. While they may occasionally become inflamed or ulcerated, "infection" is not a standard clinical presentation. * **D. Malignant transformation:** While this is the most significant *complication* (the adenoma-carcinoma sequence), it is a pathological process rather than a presenting symptom. A polyp that has already transformed into a malignancy usually presents as altered bowel habits or weight loss. **NEET-PG High-Yield Pearls:** * **Juvenile Polyps:** The most common type of polyp in children; they typically present with painless profuse rectal bleeding and may even prolapse through the anus. * **Villous Adenomas:** These have the highest risk of malignancy and can uniquely present with **secretory diarrhea** leading to hypokalemia (due to excessive mucus production). * **Gold Standard Investigation:** Colonoscopy is the investigation of choice as it allows for both diagnosis and therapeutic polypectomy.

Q: Hereditary non-polyposis colorectal cancer (HNPCC) has an increased risk of all the following cancers except?

Pancreas. **Explanation:** Hereditary Non-Polyposis Colorectal Cancer (HNPCC), also known as **Lynch Syndrome**, is an autosomal dominant condition caused by germline mutations in **DNA Mismatch Repair (MMR) genes** (primarily *MLH1, MSH2, MSH6,* and *PMS2*). This leads to microsatellite instability (MSI). While HNPCC is primarily associated with colorectal cancer, it is a multi-organ syndrome. The correct answer is **Pancreas** because, although pancreatic cancer can occur in Lynch Syndrome, its association is significantly weaker compared to the other options. In the context of standard NEET-PG patterns and the **Amsterdam II Criteria**, the "core" extracolonic cancers are more frequently tested. * **Option A (Endometrium):** This is the **most common** extracolonic malignancy in Lynch Syndrome. The lifetime risk is approximately 40-60%, often appearing before the colorectal primary. * **Option B (Ovary):** Ovarian cancer is a well-documented component of Lynch Syndrome, with a lifetime risk of approximately 10-12%. * **Option C (Stomach):** Gastric cancer is the second most common extracolonic GI malignancy in these patients (after the colon), particularly in Asian populations. **High-Yield Clinical Pearls for NEET-PG:** * **Amsterdam II Criteria (3-2-1 Rule):** 3 relatives with Lynch-associated cancer (Colorectum, Endometrium, Small bowel, Ureter/Renal pelvis); 2 generations; 1 diagnosed before age 50. * **Bethesda Criteria:** Used to determine which colorectal tumors should be tested for MSI. * **Tumor Location:** HNPCC tumors are characteristically **right-sided** (proximal to splenic flexure) and occur at a young age (~45 years). * **Other associated sites:** Small bowel, hepatobiliary tract, brain (Turcot Syndrome), and skin (Muir-Torre Syndrome).

Q: Familial adenomatous polyposis is characterized by all of the following except:

Autosomal recessive transmission. **Explanation:** **Familial Adenomatous Polyposis (FAP)** is a hereditary colorectal cancer syndrome caused by a germline mutation in the **APC (Adenomatous Polyposis Coli) gene** located on chromosome **5q21**. 1. **Why Option A is the correct answer:** FAP follows an **Autosomal Dominant** pattern of inheritance, not recessive. A child of an affected parent has a 50% chance of inheriting the mutation. Approximately 25% of cases arise from *de novo* mutations without a family history. 2. **Analysis of other options:** * **Option B:** By definition, classic FAP is characterized by the development of **hundreds to thousands** of adenomatous polyps throughout the colon and rectum, typically appearing in the second decade of life. * **Option C:** FAP is a systemic predisposition to polyps. **Duodenal adenomas** (especially in the periampullary region) occur in up to 90% of patients and are the second leading cause of cancer death in FAP after colorectal cancer. * **Option D:** FAP often presents with **extra-intestinal manifestations**. When associated with osteomas, soft tissue tumors (desmoids), and dental abnormalities, it is known as **Gardner’s Syndrome**. Association with CNS tumors (medulloblastoma) is known as **Turcot’s Syndrome**. **High-Yield Clinical Pearls for NEET-PG:** * **CHRPE:** Congenital Hypertrophy of Retinal Pigment Epithelium is the earliest detectable clinical sign of FAP. * **Management:** Prophylactic **Proctocolectomy** is the treatment of choice, usually performed in late teens or early 20s, as the risk of progression to colorectal carcinoma is **100%** by age 40-50. * **Screening:** Annual flexible sigmoidoscopy starting at age 10-12 for at-risk relatives.

Question 1

Which type of haemorrhoids is treated by the injection of a sclerosing agent?

Accepted Answer

Internal haemorrhoids

Answer

External haemorrhoids

Answer

Prolapsed haemorrhoids

Answer

Thrombosed haemorrhoids

Question 2

In a 27-year-old male, what is the most common cause of a colo-vesical fistula?

Accepted Answer

Crohn's disease

Answer

Ulcerative colitis

Answer

Tuberculosis

Answer

Colon cancer

Question 3

A 56-year-old man presents with a several-week history of intermittent bright red bloody bowel movements. The blood coats the outside of the stools and is visible in the toilet bowl and on toilet paper. He reports constipation for the past two months and a change in stool caliber to pencil-thin. He denies pain. What is the most likely diagnosis?

Accepted Answer

Cancer of the rectum

Answer

Anal fissure

Answer

Cancer of the cecum

Answer

External hemorrhoids

Question 4

Gardner's syndrome is a rare hereditary disorder involving the colon. It is characterized by

Accepted Answer

Polyposis of the colon, osteomas, epidermal inclusion cysts, and fibrous tumors in the skin

Answer

Polyposis of the colon, cancer of the thyroid, and skin tumors

Answer

Polyposis of the jejunum, pituitary adenoma, and skin tumors

Answer

Polyposis of the gastrointestinal tract, cholangiocarcinoma, and skin tumors

Question 5

What is true about the treatment of carcinoma of the left colon with acute obstruction?

Accepted Answer

All of the above

Answer

Haman's procedure

Answer

Left colectomy with anastomosis

Answer

Proximal colostomy

Question 6

In which of the following conditions, local excision in rectal carcinoma cannot be performed?

Accepted Answer

T1 and T2 cancer with lymph node involvement

Answer

Lesion located within 10 cm of the dentate line

Answer

Lesion measuring 2.7 cm

Answer

Involvement of less than 30% of the bowel circumference

Question 7

Which of the following are treatments for solitary rectal ulcer?

Accepted Answer

Rectopexy and Sclerosant injection

Answer

Rectopexy and Banding

Answer

Sclerosant injection and Rectopexy

Answer

Laxatives and Sclerosant injection

Question 8

Rectal polyps most commonly present as which of the following?

Accepted Answer

Bleeding

Answer

Obstruction

Answer

Infection

Answer

Malignant transformation

Question 9

Hereditary non-polyposis colorectal cancer (HNPCC) has an increased risk of all the following cancers except?

Accepted Answer

Pancreas

Answer

Endometrium

Answer

Ovary

Answer

Stomach

Question 10

Familial adenomatous polyposis is characterized by all of the following except:

Accepted Answer

Autosomal recessive transmission

Answer

More than 100 polyps in the colorectal area

Answer

Polyps seen in the duodenum

Answer

Extra-intestinal manifestations are present

Colorectal Surgery — MCQs

Colorectal Surgery — MCQs

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