Rectum MCQs

Sigmoidoscope length should be 60cm. Rigid sigmoidoscope is 25 cm is correct In the past, the sigmoidoscope was a rigid stainless steel instrument of variable diameter and normally 25 cm in length , but this has been replaced by disposable plastic instruments. The rectum must be empty for proper inspection. Direct inspection of the rectal mucosa may alert the clinician to inflammation or This procedure can be performed in the outpatient setting. Reference: Bailey & Love's short practice of surgery, chapter 79, Edition 28th, Pg: 1395

Explanation: A colonoscopy with biopsy is essential to confirm rectal carcinoma and to assess for synchronous lesions elsewhere in the colon. Biopsy provides histological confirmation and influences staging and management decisions. Explanation of other options: CT scan of the abdomen (Option A): Helps in staging but not the initial confirmatory step. Rigid sigmoidoscopy and biopsy (Option B): Limited to distal rectum and sigmoid; cannot assess entire colon. Barium enema (Option D): Largely replaced by colonoscopy, which is superior for diagnosis and biopsy. Key Takeaways: Colonoscopy + biopsy = diagnostic and rules out synchronous cancers. CT/MRI = staging investigations, not primary diagnostic.

The large bowel including the colon and rectum is a tube of variable diameter, approximately 150 cm in length. The terminal ileum empties into the cecum through a thickened, nipple-shaped invagination, the ileocecal valve. The cecum is a capacious sac-like segment of the proximal colon, with an average diameter of 7.5 cm and length of 10 cm. Although it is distensible, acute dilation of the cecum to a diameter of more than 12 cm, which can be measured by a plain abdominal radiograph, can result in ischemic necrosis and perforation of the bowel wall. Surgical intervention may be required when this degree of cecal distention is caused by obstruction or pseudo-obstruction Reference: Sabiston textbook of Surgery, chapter: 52, Edition: 21 st , Pg: 1321

Clinically, FAP is characterized by early development of a wide range of colorectal adenomatous polyps after the second decade of life and many extracolonic manifestations. Patients with FAP may be asymptomatic or may present with bleeding, diarrhoea, abdominal pain, or mucous discharge per rectum. Other symptoms such as anaemia, obstruction, or weight loss usually occur as polyps grow larger in size or number and may foreshadow the presence of cancer. A variety of benign and malignant extracolonic manifestations have been described in FAP. These include gastroduodenal adenomas and carcinoma, desmoids, osteomas, epidermoid cysts, papillary thyroid carcinoma, small bowel polyps and carcinoma, congenital hyperplasia of the retinal pigment epithelium (CHRPE), and dental anomalies. Reference : Sabiston textbook of Surgery, chapter: 52, Edition: 21 st , Pg: 1368

Anatomy of the rectum The rectum measures approximately 15 cm in length It is divided into lower, middle and upper thirds The blood supply consists of superior, middle and inferior rectal vessels The lymphatic drainage follows the blood supply. The principal route of drainage is upwards along the superior rectal vessels to the para-aortic nodes, although the lower rectum can drain to lymphatics along the lateral pelvic side walls Reference: Bailey & Love's short practice of surgery, chapter 79, Edition 28th, Pg: 1393

The lower third of the rectum is separated by distinct fascial layers from the prostate/vagina anteriorly (Denonvilliers fascia), and from the coccyx and lower two sacral vertebrae posteriorly (Waldeyer's fascia). These fascial layers are surgically important as they act as barriers to malignant invasion and form the anatomical envelope for total mesorectal excision (TME) to achieve complete oncological clearance of rectal cancer. Reference: Bailey & Love's short practice of surgery, chapter 79, Edition 28th, Pg: 1393