Colorectal Surgery Practice Questions

Q: What is the recommended surgical treatment for lymphoma of the appendix?

Right hemicolectomy. **Explanation:** The appendix is an uncommon site for primary gastrointestinal lymphoma, with **Non-Hodgkin Lymphoma (NHL)** being the most frequent histological type. Unlike simple appendicitis or small carcinoid tumors (under 1 cm) which can be managed by a simple appendectomy, lymphoma of the appendix requires a more radical oncological approach. **Why Right Hemicolectomy is Correct:** The standard of care for appendiceal lymphoma is a **Right Hemicolectomy**. This is because lymphoma of the appendix often involves the base of the cecum and requires an adequate lymphadenectomy (removal of the ileocolic lymph node chain) for accurate staging and local control. Since the lymphatic drainage of the appendix follows the ileocolic artery, a right hemicolectomy ensures the removal of the primary tumor with clear margins and the associated regional lymph nodes. **Why Other Options are Incorrect:** * **Extended Right Hemicolectomy:** This involves removing the transverse colon up to the splenic flexure (supplied by the middle colic artery). This is unnecessary for appendiceal lymphoma unless there is direct contiguous spread to the transverse colon. * **Left/Extended Left Hemicolectomy:** These procedures involve the descending and sigmoid colon. They are anatomically irrelevant to the appendix, which is located in the right iliac fossa. **High-Yield Clinical Pearls for NEET-PG:** * **Most common tumor of the appendix:** Carcinoid tumor (Neuroendocrine tumor). * **Management of Carcinoid:** Appendectomy if 2 cm, involves the base, or shows mesoappendiceal invasion. * **Lymphoma Presentation:** Often mimics acute appendicitis; diagnosis is frequently made post-operatively on histopathology. * **Post-op Care:** Following a right hemicolectomy, patients with lymphoma often require systemic chemotherapy (e.g., CHOP regimen) depending on the stage and subtype.

Q: Which of the following is the investigation of choice for assessment of depth of penetration and perirectal node involvement in rectal cancer?

MRI scan. **Explanation:** The assessment of rectal cancer requires accurate local staging to determine the need for neoadjuvant therapy. **1. Why MRI is the Correct Answer:** High-resolution **Pelvic MRI** is currently the **investigation of choice (Gold Standard)** for the local staging of rectal cancer. It provides superior soft-tissue contrast, allowing for precise evaluation of the **depth of tumor penetration (T-stage)** and the involvement of **perirectal lymph nodes (N-stage)**. Crucially, MRI is the only modality that can accurately predict the **Circumferential Resection Margin (CRM)**, which is the most important prognostic factor for local recurrence. **2. Why other options are incorrect:** * **CT Scan Pelvis:** While excellent for detecting distant metastasis (M-stage) in the liver or lungs, CT has poor soft-tissue resolution for the rectal wall layers and cannot accurately distinguish between T2 and T3 lesions. * **Double Contrast Barium Enema:** This is a luminal study used to detect mucosal lesions or synchronous tumors. It provides no information regarding the depth of wall invasion or nodal status. * **Transrectal Ultrasound (TRUS):** TRUS is highly accurate for very early (T1) lesions and distinguishing them from T2. However, it is operator-dependent, has a limited field of view for deep nodes, and cannot be used in stenosing/obstructive growths where the probe cannot pass. **Clinical Pearls for NEET-PG:** * **Staging Summary:** MRI for Local Staging (T & N); CT Chest/Abdomen for Distant Staging (M). * **Distance from Anal Verge:** The most important factor in deciding between Anterior Resection (AR) and Abdominoperineal Resection (APR). * **Total Mesorectal Excision (TME):** The standard surgical technique where the rectum and its surrounding lymphovascular fatty tissue are removed intact.

Q: What is true regarding colovesical fistula?

Most commonly presents with pneumaturia. **Explanation:** A colovesical fistula is an abnormal communication between the colon and the urinary bladder. It is a high-yield topic in surgical gastroenterology. **1. Why Option A is correct:** The hallmark clinical presentation of a colovesical fistula is **pneumaturia** (passage of gas in urine) and **fecaluria** (passage of stool in urine). Pneumaturia occurs because the pressure gradient allows gas from the bowel lumen to enter the bladder. It is the most common and pathognomonic symptom. Patients also frequently present with recurrent UTIs or "refractory cystitis" caused by polymicrobial enteric flora. **2. Why the other options are incorrect:** * **Option B:** The most common cause of colovesical fistula is **Diverticulitis** (approx. 65-75% of cases), followed by malignancy and Crohn’s disease. While colonic cancer can cause it, it is not the *most* common cause. * **Option C:** It is significantly **more common in males**. In females, the uterus and broad ligaments act as a protective anatomical barrier between the bladder and the sigmoid colon. * **Option D:** Barium enema has a low sensitivity (approx. 20-30%) for diagnosing the fistula tract. The **CT scan with oral or rectal contrast** (but not IV contrast initially) is the investigation of choice, showing air in the bladder or thickened bowel loops adjacent to the bladder. **Clinical Pearls for NEET-PG:** * **Most common site:** Between the sigmoid colon and the dome of the bladder. * **Diagnostic Gold Standard:** While CT is the best initial imaging, **Cystoscopy** is often performed to visualize the "bull’s eye" sign (localized edema and erythema at the fistula site). * **Bourne Test:** A high-yield diagnostic test where the patient’s urine is centrifuged after a barium enema to look for radiopaque particles.

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.

Question 1

A 65-year-old male patient presents with a history of early morning bloody diarrhea, change in bowel habits, intermittent obstruction, a feeling of incomplete evacuation, and tenesmus. There is no positive family history for any carcinoma. What is the treatment of choice in this case?

Accepted Answer

Total mesorectal excision

Answer

Hamann's procedure

Answer

Anterior resection

Answer

Abdominoperineal resection

Question 2

What is the recommended surgical treatment for lymphoma of the appendix?

Accepted Answer

Right hemicolectomy

Answer

Extended right hemicolectomy

Answer

Left hemicolectomy

Answer

Extended left hemicolectomy

Question 3

Which of the following is the investigation of choice for assessment of depth of penetration and perirectal node involvement in rectal cancer?

Accepted Answer

MRI scan

Answer

CT scan pelvis

Answer

Double contrast barium enema

Answer

Transrectal ultrasound

Question 4

A patient with rectal carcinoma has a tumor invading through the muscularis propria into the perirectal tissues, along with two enlarged lymph nodes. What is the recommended management strategy?

Accepted Answer

Preoperative chemoradiation followed by surgical resection

Answer

Surgery only

Answer

Surgery with adjuvant chemotherapy

Answer

Palliative chemoradiation

Question 5

What is true regarding colovesical fistula?

Accepted Answer

Most commonly presents with pneumaturia

Answer

Most commonly caused by colonic cancer

Answer

More common in females

Answer

Readily diagnosed on barium enema

Question 6

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 7

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 8

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 9

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 10

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

Colorectal Surgery — MCQs

Colorectal Surgery — MCQs

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