SU28.13-17 | Intestinal, Appendicular and Anorectal Surgery — Glossary

Removal of the rectum and anus with a permanent colostomy; used as salvage for anal cancer and for very low rectal cancers.

Acute inflammation of the vermiform appendix, usually following luminal obstruction; the commonest abdominal surgical emergency.

The stepwise progression of a benign colonic adenoma to invasive carcinoma, the rationale for screening and polypectomy.

A clinical scoring system (out of 10) combining symptoms, signs and laboratory findings to estimate the probability of acute appendicitis.

The terminal ~3–4 cm of the gastrointestinal tract, from the anorectal junction to the anal verge, divided by the dentate line.

Longitudinal mucosal folds of the upper anal canal, joined inferiorly by the anal valves that form the dentate line.

A longitudinal tear of the sensitive anoderm, characteristically in the posterior midline, causing severe pain on defaecation; the chronic triad is sentinel tag, ulcer and hypertrophied papilla.

The predominant anal cancer, arising at or below the dentate line and strongly associated with HPV; treated primarily by chemoradiotherapy.

A surgical join between two bowel ends, which heals only with a good blood supply and no tension.

A congenital anomaly of the terminal rectum/anal canal, classified high or low according to its position relative to the puborectalis/levator ani sling.

The muscular ring at the anorectal junction formed by the puborectalis and the upper internal/external sphincters; division causes incontinence.

Surgical removal of the appendix, performed laparoscopically or open, the definitive treatment of acute appendicitis.

Small fatty tags hanging from the surface of the large intestine.

A localised collection of pus arising from a perforated appendix, requiring drainage.

An inflamed or perforated appendix walled off by omentum and adjacent bowel into a palpable mass with no drainable pus.

A tumour marker used to monitor colorectal cancer after treatment rather than to make the diagnosis.

Bowel obstructed at two points so pressure cannot vent, risking perforation (the caecum first by Laplace's law); seen in volvulus and LBO with a competent ileocaecal valve.

Adenocarcinoma of the colon or rectum; right-sided tumours present with anaemia and a mass, left-sided with obstruction and altered bowel habit.

Transmural inflammatory bowel disease with skip lesions anywhere from mouth to anus, non-caseating granulomas, and a tendency to fistulae and strictures.

The line at the anal valves marking the hindgut–proctodaeum (endoderm–ectoderm) junction, dividing the anal canal's epithelium, blood supply, venous and lymphatic drainage and innervation.

Conservative management of simple small-bowel obstruction — nil by mouth, intravenous fluids and nasogastric decompression.

Voluntary striated muscle surrounding the anal canal, continuous with the puborectalis, providing the voluntary squeeze for continence.

A hardened plug of faecal material that obstructs the appendiceal lumen and initiates appendicitis.

A chronic epithelialised track between the anal canal and perianal skin, usually following a cryptoglandular abscess; classified by its relation to the sphincters (Parks).

Laying open a low fistula-in-ano that involves little sphincter muscle, the standard treatment for simple fistulae.

Diffuse inflammation of the peritoneal cavity from free perforation when the appendix is not walled off, common in young children; a surgical emergency.

A rule predicting a fistula's track: an external opening anterior to the transverse anal line runs radially to the dentate line, while a posterior opening curves to the posterior midline.

Grade I bleed without prolapse; II prolapse on straining and reduce spontaneously; III prolapse and need manual reduction; IV irreducible/permanently prolapsed.

The watershed at the splenic flexure, the SMA–IMA junction, a classic site of ischaemic colitis.

Symptomatic enlargement of the anal vascular cushions; internal arise above the dentate line (painless bleeding), external below it (painful when thrombosed).

The sacculations of the large bowel produced by the taenia coli; on X-ray their folds do not cross the full lumen.

Congenital absence of ganglion cells in the distal bowel causing functional obstruction and failure to pass meconium; diagnosed by rectal biopsy.

The artery of the hindgut, supplying the distal one-third of the transverse colon, the descending and sigmoid colon and the upper rectum.

A branch of the internal pudendal artery (systemic) supplying the anal canal below the dentate line and the sphincters.

An involuntary smooth-muscle continuation of the rectal circular muscle, providing most of the resting anal tone.

Dilated anal cushions arising above the dentate line, draining to the portal system and presenting with painless bright-red bleeding.

Planned removal of the appendix some weeks after conservative resolution of an appendicular mass or abscess (classically about 6 weeks).

Blockage of the bowel lumen producing colicky pain, vomiting, distension and absolute constipation; classified by level (small vs large bowel) and mechanism (simple vs strangulating).

Telescoping of one bowel segment into the next, classically ileocolic in infants, presenting with colicky pain, a sausage-shaped mass and red-currant-jelly stool (target sign on ultrasound).

Colonic ischaemia, classically affecting the watershed zones, when arterial perfusion falls.

The caecum, colon, rectum and anal canal, ~1.5 m long, characterised by taenia coli, haustra and appendices epiploicae.

Obstruction of the colon, commonest cause colorectal carcinoma then volvulus, with marked distension and peripheral haustra on the X-ray.

Surgical division of part of the internal anal sphincter for a chronic fissure refractory to medical therapy; its recognised risk is minor incontinence to flatus.

Enlargement of appendiceal lymphoid tissue (common in the young, often post-viral) that obstructs the lumen and precipitates appendicitis.

The continuous anastomotic arterial channel along the inner border of the colon that links the SMA and IMA territories.

The point of maximal tenderness in appendicitis, at the junction of the lateral one-third and medial two-thirds of a line from the right anterior superior iliac spine to the umbilicus.

The fatty fascial envelope around the rectum carrying its lymphovascular supply and draining nodes; removed intact during total mesorectal excision.

The classic shift of appendicitis pain from a central peri-umbilical ache (visceral) to a sharp, localised right iliac fossa pain (parietal) as the inflammation involves the overlying peritoneum.

Obstruction in the newborn from causes such as duodenal/jejunoileal atresia, malrotation with midgut volvulus, Hirschsprung's disease, meconium ileus or anorectal malformation.

The sphincter-preserving chemoradiotherapy regimen (5-fluorouracil, mitomycin C and radiotherapy) that is the primary treatment of anal squamous cell carcinoma.

Pain on internal rotation of the flexed right hip, suggesting an inflamed pelvic appendix.

Conservative management of a settling appendicular mass — IV fluids, antibiotics, and marking/monitoring the mass and vital signs — followed by interval appendicectomy, abandoned if the patient deteriorates.

A collection of pus arising from infected cryptoglandular glands, tracking into perianal, ischiorectal, intersphincteric or supralevator spaces; treated by incision and drainage.

A hair-containing sinus of the natal cleft, prone to recurrent infection and abscess, treated by drainage and excision.

Permanent circular mucosal folds of the small intestine that span the whole lumen and increase absorptive surface; their full-lumen appearance identifies small bowel on X-ray.

Rare septic thrombophlebitis of the portal venous system from appendicitis, causing liver abscesses.

The venous drainage of the intestine via the superior and inferior mesenteric veins to the liver, explaining hepatic metastasis of bowel cancer.

Pain on extension of the right hip, suggesting a retrocaecal appendix irritating the psoas muscle.

A sling of the levator ani that pulls the anorectal junction forward to create the anorectal angle essential for continence.

Protrusion of rectal tissue through the anus — partial (mucosal) or complete (full-thickness procidentia) — repaired by an abdominal (rectopexy) or perineal procedure.

The terminal ~12–15 cm of the large bowel, from the rectosigmoid junction (S3) to the anorectal junction, surrounded by the mesorectum.

Pain felt in the right iliac fossa when the left iliac fossa is pressed, supporting a diagnosis of appendicitis.

A thread passed through a fistula track to drain it and preserve continence (and sometimes to gradually divide a high fistula), used where simple laying-open would risk incontinence.

Malabsorption and nutritional failure after extensive small-bowel resection, typically when under about 200 cm of small bowel remains.

The jejunum and ileum (with the duodenum), ~6 m long in the living adult, suspended on mesentery and supplied by the superior mesenteric artery.

Obstruction of the small intestine, commonest causes adhesions then hernia, with early prominent vomiting and central valvulae conniventes on the X-ray.

Obstruction in which the blood supply is compromised, causing ischaemia; signalled by constant pain, tenderness, tachycardia and fever, and demanding urgent surgery.

The watershed at the rectosigmoid junction, a site vulnerable to ischaemia.

The artery of the midgut, supplying the small intestine, caecum/appendix, ascending colon and proximal two-thirds of the transverse colon.

The continuation of the inferior mesenteric artery supplying the rectum and the anal canal above the dentate line.

Three longitudinal bands of the colon's outer muscle that, being shorter than the gut, gather it into haustra.

A painful, tense, clotted haemorrhoid at the anal verge below the dentate line, which can be excised early or managed conservatively.

Removal of the rectum within its intact mesorectal fascial plane, the strongest determinant of local cure in rectal cancer surgery.

Acute, severe colonic dilatation with systemic toxicity, a dangerous complication of ulcerative colitis (and other colitides).

Mucosal inflammatory bowel disease that is continuous from the rectum upwards, confined to the colon, with risk of toxic megacolon; colectomy is curative.

A cluster of congenital anomalies (Vertebral, Anal, Cardiac, Tracheo-Esophageal, Renal, Limb) screened for in neonates with anorectal malformations.

The three transverse mucosal folds within the rectum corresponding to its lateral curves.

The supplying artery (and its draining nodes) of a bowel segment, taken at its origin during an oncological resection.

Finger-like mucosal projections of the small intestine that increase absorptive surface area; absent from the large bowel.

A twist of bowel on its mesentery, most often the sigmoid colon, producing a massively distended loop with a coffee-bean (omega) sign on the radiograph.

A region at the boundary of two arterial territories with marginal collateral flow, vulnerable to ischaemia; in the colon the splenic flexure (Griffiths') and rectosigmoid (Sudeck').