Conditions of the small bowel,
the colon, rectum and anus
Dr Ntakiyiruta Georges,Mmed,FCSECSA
Lecturer
Department of Surgery
Faculty of Medicine
National University of Rwanda
• Meckel’s diverticulum
• Typhoid
• Tuberculosis
• Small bowel obstruction
• Appendicitis
• Inflammatory bowel disease
• Diverticular disease
• Volvulus and large bowel obstruction
• Anal conditions(haemorroids, rectal prolapse, perianal
hematoma, fissure in ano, anorectal abscess,
fistula-in-ano)
Meckel’s diverticulum
• It is a remnant of of the vitellointestinal duct
of the embryo
• Classically it occurs in 2% of patients, 2inches
long, and 2feet from the ileocecal junction
(‘rule of 2s’)
• It occurs on the antimesenteric border of the
terminal ileum
Symptoms and signs
• Symptomless
• Incidental findings at laparotomy
• Symptoms typical of acute appendicitis may
occur
• Rectal bleeding (ectopic gastric mucosa)
• Rarely, umbilical discharge(fistula), intestinal
obstruction(due to entrapment around the
band from the apex of the diverticulum to the
back of the umbilicus), small bowel volvulus,
or intussusception(ileo-ileal)
Investigations
• Technetium scan for GI bleeding may show
gastric mucosa in a Meckel’s
• Laparotomy is required for complications of
Meckel’s- the cause is not usually apparent
until laparotomy is undertaken
Treatment
• Excision of the diverticulum
Typhoid
• Caused by salmonella typhi
• It is endemic in Rwanda.
• The organism enters the Peyer’s patches and may
result in perforation or bleeding usually involving the
ileum.
• This usually occurs during the third week of the
disease
• The patient shows signs of perforation and
generalized peritonitis
• Surgical closure of the perforation is required
Small bowel obstruction
• Mechanical obstruction of the SB may be
– simple(one point of obstruction)
– Or closed loop(obstruction at 2 points enclosing a
segment of bowel)
• If the bowel is viable, the obstruction is
termed non strangulating
• If the blood supply is compromised,
strangulating obstruction occurs with
subsequent infarction of bowel.
• Stranglation occurs when the obstructing
mechanism cuts off the mesenteric arterial
blood supply; e.g. the neck of the sac with a
loop of bowel trapped in a hernial sac, or the
twist of a volvulus
• Mechanical obstruction is more common in
the small bowel than in the large bowel
Causes
• In the lumen: gallstone ileus, food
bolus(following pylorus destroying operations,
i.e. pyloroplasty)
• In the wall: congenital atresia, tumours, e.g.
lymphoma or carcinoma
• Outside the wall: herniae, adhesions, volvulus,
intussusception
Symptoms and signs
• Colicky abdominal pain; Vomiting; Constipation;
Abdominal distension
• Symptoms depend on whether the obstruction is
high or low.
• High obstruction🡪early vomiting(bilious), and late
constipation
• Low obstruction🡪early constipation, and late
vomiting(faeculent), and marked distension
• Tympanitic abdomen
• High-pitched tinkling bowel sounds
• Hernial orifices should be carefully examined
• Pyrexia, tachycardia, continuous pain and
localized tenderness suggest actual or
impending strangulation.
Investigations
• Hb; FBC; WCC with neutrophilia may indicate
strangulation; U&Es;
• AXR: distended loops of small bowel in central
abdomen. Erect films show air fluid levels.
Absent or diminished colonic gas. Dilated
proximal small bowel shows lines close
together (valvulae conniventes) crossing
completely the lumen of the bowel. Look for
gas in the biliary tree (gallstone ileus with
cholecystoduodenal fistula)
Treatment: conservative
• Intravenous fluids and nasogastric aspiration
• Nil orally
• 2-hourly temperature and pulse
• Abdominal examination 8-hourly
Some cases of simple mechanical obstruction, e.g.
due to adhesions, will settle on this regimen
Treatment: indications for surgery
• Strangulating obstruction, e.g. a tender
irreducible hernia requires urgent surgery
• If a conservative ”drip and suck”has been
undertaken for obstruction, surgery is
indicated for signs of incipient
strangulation(pyrexia, tachycardia, localized
tenderness)
• Surgery is also required for simple obstruction
which fails to settle, e.g. adhesions
• At surgery the affected bowel is inspected for
viability.
• Indications of non-viability include:
– Absence of peristalsis
– Loss of normal sheen
– Loss of pulsation in bowel mesentry
– Colour: green or black bowel is non-viable and
resection is required. Plum-coloured bowel may
respond to wrapping for a few minutes in warm
saline-soaked packs. If colour returns and
transmission of peristaltic wave, it is viable.
Prognosis
• Small bowel obstruction has a very low
mortality rate if it is simple.
• Strngulating obstruction increases the
mortality and if small bowel resection is
required, esp. in the elderly, the mortality rate
may reach 25%
Appendicitis
• When there is an obstruction in the lumen of
the appendix either by a faecolith or foreign
body or by enlargement of lymphoid follicles
in its wall.
• Most often children, teenagers and young
adults.
• Rare in the extremes of life.
• Rare causes include carcinomas of the caecum
obstructing the appendiceal lumen, carcinoid
tumours and obstructing fibrous bands
Symptoms and signs
• Central abdominal cramping or colicky pain
• Nausea. Vomiting is uncommon.
• Occasionally the patient may pass a loose
stool
• Central abdominal pain lasts approximately
8hours
• It is followed by the development of a sharp,
stabbing somatic type of pain in the RIF made
worse by coughing or moving
• Low grade pyrexia(37.2-37.8C)
• White furred tongue
• Tachycardia
• Tender with guarding in RIF over McBurney’s
point
• PR examination: tender anteriorly in the
rectovesical or rectouterine pouch
• In infants diarrhoea and vomiting may be the
only symptoms. This may lead to difficulty in
diagnosis and confusion with gastroenteritis.
• In elderly patients there may be confusion and
later shock may develop.
Investigations
• WCC: usually > 10X109/L with neutrophil
leukocytosis
• USS: may show a mass or abscess; not useful
in early appendicitis
DD:
DD
• In the classical case: mesenteric adenitis,
Meckel’s diverticulitis, Crohn’s
disease(regional ileitis);mesenteric embolus
and right sided colonic diverticulitis
• In the atypical case, other causes of
intra-abdominal pathology, urinary tract
disease, gynecological problems and
extra-abdominal conditions must considered.
• Abdominal disease: cholecystitis,
gastroenteritis, pancreatitis, perforated DU,
intestinal obstruction, diverticulitis,
non-specific abdominal pain
• Urinary tract: acute pyelonephritis, renal colic,
cystitis,
• Gynecological causes: salpingitis, ectopic
pregnancy, degeneration of a fibroid,
Mittelschmerz. Pelvic inflammatory disease
• Extra-abdominal causes: referred pain from
nerve roots, e.g. herpes zoster; right lower
lobar pneumonia, right-sided testicular torsion
• The treatment of acute appendicitis is
Appendicectomy. Prophylactic metronidazole
should be given 1hour preoperatively to
reduce the risk of wound infection.
Complications
• It may resolve spontaneously
• It may give rise to an Appendix mass
• It may perforate giving rise to generalized peritonitis
or it may perforate amidst of local adhesions giving
rise to an Appendix abscess
• if the symptoms have been there for 48hours(48hour
rule) and the dx is truly appendicitis, then the patient
should either have developed an appendix mass or
generalzed peritonitis
• If neither, then the DX should be reviewed
Appendix mass
• Omentum and small bowel adhere to the inflamed
appendix
• 2-5days after onset of initial symptoms
• This should be initially treated conservatively. Mark
out the site of the mass, IV fluids, analgesia and
antibiotics
• If the mass resolves, interval appendicectomy after
3months
• If it gets bigger, it is likely that an abscess is forming
Appendix abscess
• The appendix mass enlarges and the
temperature fails to settle
• Patient may appear toxic with tachycardia
• Either surgical drainage or appendicectomy, or
percutaneous insertion of a drain under USS
control. Interval appendicectomy requored
later.
• Other complications: subphrenic abscess,
paralytic ileus, septicaemia, portal pyaemia
Appendicitis in pregnancy
• No commoner than at other times
• Pain and tenderness are higher because of
displacement of the appendix by the enlarging
uterus
• Prompt assessment and interventionare
essential
• Risk of abortion in the first trimester but if
treatment is delayed until perforation occurs,
the risk is considerably higher ~ 25%
Volvulus
• This a twisting of a loop of bowel around its
mesenteric axis. Partial or complete
obstruction may result.
• Occlusion of the arteries at the base of the
involved mesentery leads to gangrene and
perforation
Sigmoid volvulus
• Middle-aged and elderly males are more often
affected.
• A large redundant sigmoid colon and
constipation are predisposing factors
Symptoms and signs
• Sudden onset of lower abdominal colicky pain
associated with gross abdominal distension
• Distended tympanic abdomen
• Investigations: AXR, distended loop of bowel
the shape of a coffee bean arising out of the
pelvis ; barium enema: the barium column
resembles a bird’s beak.
Treatment
• Decompression by sigmoidoscopy. A rectal flatus
tube should be left in situ for 48hours.
• If the patient is fit, elective resection of the sigmoid
is carried out at a later date
• If decompression not successful, laparotomy with
resection;
• If decompression is not successful or signs of
gangrene or perforation, laparotomy with resection,
the two ends are brought out as a double-barreled
colostomy(Paul Mickulicz procedure)
Caecal volvulus
• When caecum and ascending colon are excessively
mobile(the caecum has retained its mesentery)
• Sudden onset of abdominal pain, vomiting and
constipation. Tympanitic mass in LUQ
• Investigations: AXR🡪dilated caecum in LUQ
• R/ Laparotomy.
– If the bowel is viable, untwisting and caecostomy. Right
hemicolectomy may be the best option as high recurrence
rate
– If gangrenous bowel, right hemicolectomy is required
Large bowel obstruction
• Major causes: carcinoma, diverticular disease
and sigmoid colon
• In 20%, the ileocaecal valve is competent and
decompression into small bowel does not
occur. Closed-loop obstruction therefore
occurs with progressive distension of the
caecum. Ischaemia and perforation of the
caecum may occur.
S&S
• Colicky abdominal pain,constipation and
vomiting(late)
• Constant severe pain suggests ischemic bowel
• Distended tympanitic abdomen
• Obstructed bowel sounds
• Rectum may be empty on PR
Investigations
• Sigmoidoscopy: rectosigmoid lesions may be
seen
• AXR: distended large bowel with air/fluid
levels surrounding the abdomen
• Limited barium enema 🡪”apple core” lesion
Treatment
• Drip and suck. Correct electrolyte imbalance
• A caecum 10cm or > in diameter on radiograph is
urgent indication for surgery
• Laparotomy with decompression of the obstruction
• Right sided lesions: right hemicolectomy; left sided
lesions by left hemicolectomy with covering
colostomy
• Low left-sided lesions: resection of the tumour with
Hartmann’s procedure
Anal conditions
• Haemorroids
• Rectal prolapse
• Perianal haematoma
• Fissure-in-ano
• Ano-rectal abscesses
• Fistula-in-ano
• Pruritus ani
Haemorroids
• Enlarged vascular cushions in the lower
rectum and anal canal
• They are not simply varicosities. At least 10%
of the population have symptomatic
haemorroids at some time in life
• The classical position corresponds to branches
of superior haemorroidal artery occurring at
the 3 o’clock, 7 o’clock and 11 o’clock
positions with the patient in lithotomy
position
S&S
• Asymptomatic, Rectal bleeding, Prolapse,
Itching
• Piles are not painful unless they thrombose
• 1st degree piles remain in the rectum
• 2nd degree piles prolapse on defaecation but
reduce spontaneously
• 3rd degree piles prolapse and require manual
reduction
Investigations
• Sigmoidoscopy
• Proctoscopy
• Barium enema (if any doubt as to the cause of
bleeding)
Treatment
• Injection treatment: 2-3ml of phenol in
almond oil into the submucosa above the pile
• Other non-operative approaches: rubber band
ligation, cryosurgery and photocoagulation
• Large 2nd and 3rd degree piles:
haemorroidectomy
• Thrombosed piles: bed rest, analgesia, ice
packs or emergency hemorroidectomy
• Regulation of bowel habits with high-fibre diet
Complications of
haemorroidectomy
• Acute retention of urine
• Haemorrrhage
• Stricture
Rectal prolapse
• May be partial or complete
• Partial 🡪 mucosa alone; no more than a few
cm
• Complete 🡪 all layers of the rectal wall
• S &S: protruding mass from anus esp. during
defaecation. May reduce spontaneously. May
need manual reduction and eventually
becomes difficult to reduce. Blood and mucus
PR from ulceration of exposed mucosa
• Differential Dx: prolapsing hemorroids, polyps,
intussusception
• Treatment
– Mucosal prolapse: sclerosants (as for piles)
– Complete prolapse: abdominal rectopexy
(Ripstein’s procedure). Other procedures are
Delorme procedure or Thiersch wire
Peri-anal haematoma
• Acute peri-anal pain. Worse on sitting, walking
and defaecation.
• Tense, smooth, tender blue lump at anal verge
• R/
– symptoms may subside spontaneously after 2-3
days during which analgesia is given
– If patient presents in acute phase, incision under
LA
Fissure-in-ano
• A tear at the anal margin due to passage of a
constipated stool
• It is usually in the midline posteriorly but may
be occasionally anterior
• Multiple fissures --? Crohn’s disease
• S&S: acute anal pain, severe on defaecation.
Blood on toilet paper. Part the buttocks and
they may be apparent. Acute sphincter spasm.
Examination PR is impossible. Occasionally
“sentinel” pile.
• Differential Dx: trauma, carcinoma, TB, herpes,
Crohn’s disease, syphilis
• Treatment
– Conservative if mild symptoms:
• LA gel or suppository(1/2hr before defaecation); stool
softening laxative and high-fibre diet
• Apply 0.2% GTN ointment locally bid x 6weeks 🡪relax
internal sphincter
– Surgical: a lateral subcutaneous internal
sphincterotomy to relieve spasm. Laxative and
high-fibre diet. Recurrent fissure should be excised
and sent for histology
Anorectal abscess
• These develop in tissue spaces adjacent to the
anorectal area.
• They may be
– Perianal (in a hair follicle, sebaceous gland or
perianal haematoma)
– Ischio-rectal (in the ischio rectal fossa)
– Intermuscular (between internal and external
sphincters)
– Pelvirectal (from a pelvic abscess)
• S& S: constant, throbbing, perianal pain worse
on sitting. Lower abdominal pain with
pelvirectal abscess. Indurated tender mass
perianally. Boggy mass on examination PR.
Fever.
• Treatment: prompt surgical drainage to
prevent fistula formation. No role of
antibiotics except in Diabetics and
Immunocompromised.
Fistula-in-ano
• A fistula is abnormal communication between
two epithelial surfaces.
• There is internal opening in the anal canal and
one or more external openings on the perianal
skin
• The majority arise from delay in treatment or
inadequate treatment of anorectal abscesses
• Rare causes: TB, Crohn’s disease, carcinoma
Goodsall’s law
• It may be difficult to locate the internal
opening.
• If the external opening lies anterior to a line
drawn transversely through the center of the
anus, the track passes radially through a
straight line towards the internal opening. If
the external opening is behind this line the
track curves in a horseshoe manner to open
into the midline posteriorly.
Classification
• Subcutaneous
• Submucous
• Low anal(below pubo rectalis)
• High anal(opening in close relation to the
anorectal junction)
• Pelvirectal(penetrating levator ani)
Symptoms and signs
• History of abscess which drains spontaneously or was
surgically drained
• Persistent drainage of pus, mucus, blood or faecal
matter associated with perianal irritation and
discomfort
• Drainage may be intermittent
• Single opening near the anus
• examinationPR: indurated track, pressure on which
may cause discharge
• Proctoscopy or sigmoidoscopy to define internal
openings
Treatment
• The track is identified by probing and laid
open under GA, so that it heals by granulation
tissue from the base
• With high fistulae, there is a danger to
puborectalis when opening the track.
Incontinence may result. They require
specialist treatment often by a two-staged
operation