Rectum

Pelvic floor

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📘 Theme: Mock Test – 1 March 2026

Pelvic Floor Mechanics

During anorectal manometry, a patient demonstrates preservation of resting continence despite severe internal anal sphincter damage. Which structure is most responsible for maintaining continence in this scenario?

A. Pubococcygeus
B. Iliococcygeus
C. Puborectalis
D. External anal sphincter

Answer: C. Puborectalis

Explanation:
The puborectalis muscle forms a U-shaped sling around the anorectal junction and is the most critical muscle for maintaining fecal continence. Its tonic contraction maintains an acute anorectal angle, preventing involuntary stool passage. Even with internal anal sphincter damage, the puborectalis sling can preserve continence.

Teaching Points:

  • Puborectalis forms a sling at the anorectal junction.
  • Maintains anorectal angle (~80–90°) → continence.
  • Relaxes during defecation → angle straightens.
  • Dysfunction → dyssynergic defecation or fecal incontinence.
  • Key compensatory mechanism when sphincters are weak.

🔗 Practice more free colon questions:

Anal malformation

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MCQ on Newborn with Abdominal Distension
Q) Newborn with abdominal distension on day 2, not passed meconium. There is absent anal orifice. What is the next step? # NEET SS 22
✅ Answer: A. Cross table X ray

🔍 Explanation:
The first step in such cases is to rule out congenital abnormalities of the spine, sacrum, kidneys, and heart.

- The second step is a Cross-table X-ray. If the X-ray shows perineal fistula, perform Anoplasty.
- If the X-ray shows rectal gas below the coccyx, perform a PSARP (Posterior Sagittal Anorectoplasty) with or without a colostomy.
- If the X-ray shows gas above the coccyx with associated defects, perform a colostomy.

🧠 Key Point: Cross-table X-ray is crucial to determine the presence of rectal gas and other associated defects, guiding the next step in management.

📘 Reference: Table 67.14 Sabiston

Steroid Refractory Ulcerative colitis

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Q) Not used in steroid refractory severe Ulcerative Colitis ( AIIMS 2020 Nov) 

a) Infliximab
b) Azathioprine
c) Cyclosporine
d) Surgery

Ans b- Azathioprine

Cyclosporine is  immunomodulator indicated for second-line therapy in the case of severe, steroid refractory ulcerative colitis. Treatment is usually initiated after 3 to 5 days of failed steroid response

Tacrolimus is appropriate as second-line therapy in patients with severely active ulcerative colitis unresponsive to steroids.

The use of various anti–tumor necrosis factor-α  (TNF-α) monoclonal antibodies ( infliximab)  is well supported in the case of
severe ulcerative colitis refractory to steroids. 

Rectal Intussusception

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Q) Pick the true statement about rectal intussusception

a) It is a rare finding in defecography

b) When found, it is found to be a common cause of refractory constipation

c) Biofeedback therapy and fibre intake is the mainstream treatment of choice

d) Rectopexy has had good long term results