Page 18 of 20
SU28.13-17 | Intestinal, Appendicular and Anorectal Surgery — Graded Quiz
Click any question card to reveal the correct answer.
On a plain abdominal film of an obstructed abdomen, you must decide small-bowel versus large-bowel obstruction first. Which radiological feature indicates that the distended loops are large bowel rather than small bowel?
Large-bowel loops sit peripherally and show haustra that only partially cross the lumen; small-bowel loops are central with valvulae conniventes crossing the full width. Deciding which it is changes everything that follows.
On AXR: small bowel = central, valvulae conniventes cross the whole lumen; large bowel = peripheral, haustra partial. Decide SBO vs LBO first — it changes management.
Peripheral loops with partial-width haustra = large bowel; central loops with full-width valvulae conniventes = small bowel.
Click to reveal answer
During an oncological resection of a colonic tumour the surgeon takes the supplying artery at its origin together with the mesentery and lymph nodes. The colon is supplied by which two arteries reflecting its midgut/hindgut embryological seam?
The SMA supplies the midgut (to the proximal two-thirds of the transverse colon) and the IMA the hindgut (distal transverse colon to upper rectum); the splenic flexure is the watershed between them.
SMA = midgut (jejunum/ileum, caecum, ascending and proximal two-thirds of transverse colon); IMA = hindgut (distal transverse, descending, sigmoid, upper rectum); splenic flexure (Griffiths' point) is the watershed.
Colonic blood supply follows the SMA (midgut) and IMA (hindgut) — the splenic flexure is the watershed zone.
Click to reveal answer
A previously well young adult has simple adhesive small-bowel obstruction with no signs of strangulation. What is the appropriate initial management?
Simple adhesive SBO is usually managed first conservatively with 'drip and suck' (NBM, NG decompression, IV fluids); surgery is indicated if it fails or signs of strangulation develop.
Adhesive SBO: try conservative 'drip and suck' first; the trigger to operate is failure to resolve OR strangulation (constant pain, tenderness, fever, rising markers).
Simple adhesive SBO is initially conservative ('drip and suck'); operate only for failure or strangulation.
Click to reveal answer
A 70-year-old with rectal bleeding and a change in bowel habit is found to have a left-sided colonic adenocarcinoma. In the well-recognised adenoma-carcinoma sequence, the typical precursor lesion is which of the following?
Most colorectal cancers arise from adenomatous polyps via the adenoma-carcinoma sequence; right-sided cancers tend to present with anaemia and left-sided ones with obstruction/altered bowel habit. Staging uses Dukes/TNM.
CRC: adenoma-carcinoma sequence; right-sided → iron-deficiency anaemia, left-sided → obstruction/altered habit/PR bleeding; staged by Dukes/TNM.
The adenoma-carcinoma sequence begins with an adenomatous polyp.
Click to reveal answer
A patient with acute appendicitis presents five days after symptom onset with a tender mass in the right iliac fossa but is systemically well, afebrile and not peritonitic. What is the generally preferred initial management of an uncomplicated appendix mass?
An established, uncomplicated appendix mass in a well patient is usually managed conservatively (antibiotics, observation; the Ochsner-Sherren regimen), with consideration of interval appendicectomy; immediate surgery into an inflamed mass is hazardous. An abscess, by contrast, needs drainage.
Appendix mass (present several days in, well patient): conservative management ± interval appendicectomy; an appendix abscess needs drainage. Operating into an inflamed mass risks injury.
An uncomplicated appendix mass is generally managed conservatively first, not by immediate appendicectomy.
Click to reveal answer
The dentate (pectinate) line is described as 'the one boundary that changes everything' in the anal canal. What is its embryological and clinical significance?
The dentate line is the embryological junction of hindgut (endoderm) above and proctodaeum (ectoderm) below; this divides innervation (visceral/insensate above, somatic/sensate below), venous/lymphatic drainage, and epithelial type — explaining why disease above is painless and below is painful.
Dentate line: above = endoderm/visceral/insensate/portal drainage; below = ectoderm/somatic/sensate/systemic drainage. It predicts pain (painless above, painful below) before you examine.
The dentate line divides the canal into an insensate visceral zone (above) and a sensate somatic zone (below) — the embryological hindgut/proctodaeum junction.
Click to reveal answer
A patient has a perianal fistula with an external opening posterior to the transverse anal line. Applying Goodsall's rule, where is the internal opening of the track most likely to be?
By Goodsall's rule, a fistula with an external opening posterior to the transverse anal line tends to curve and open into the posterior midline, whereas an anterior external opening usually tracks radially and directly to the canal.
Goodsall's rule: posterior external opening → curving track to the posterior midline; anterior external opening → straight radial track. Useful for finding the internal opening at surgery.
Goodsall's rule: posterior external openings curve to the posterior midline; anterior openings track radially/directly.
Click to reveal answer
A diabetic man presents with a hot, exquisitely tender, fluctuant swelling beside the anus with overlying erythema and fever. What is the most appropriate definitive management of this perianal abscess?
A perianal abscess is treated by prompt incision and drainage; antibiotics alone are inadequate for a collection. Drainage relieves the sepsis, and any underlying fistula is dealt with later.
Perianal abscess → incision and drainage (antibiotics are adjunctive); watch for an underlying fistula and for necrotising infection in diabetics/immunocompromised.
An abscess needs drainage — incision and drainage is the definitive treatment, not antibiotics alone.
Click to reveal answer