6. PATHOPHYSIOLOGY
• proximal bowel dilates
• altered motility
• Below the obstruction normal peristalsis and
absorption
• Initially, proximal peristalsis is increased
• not relieved, the bowel begins to dilate
7. • flaccidity and paralysis
• prevent vascular damage
• overgrowth of both aerobic and anaerobic
organisms
• gas production
• nitrogen (90%) and hydrogen sulphide
8. • various digestive juices
• fluid accumulates within the bowel wall
secreted
• absorption from the gut is retarded
9. • Dehydration and electrolyte loss
• reduced oral intake
• defective intestinal absorption
• Vomiting
• sequestration in the bowel lumen
10. STRANGULATION
• venous return is compromised before the arterial
supply
• increase in capillary pressure
• local mural distension
• loss of intravascular fluid and red blood cells
intramurally and extraluminally
11. • Once the arterial supply is impaired
• haemorrhagic infarction
• marked translocation and systemic exposure to
anaerobic organisms with their associated toxins
• morbidity of intraperitoneal strangulation is far
greater than with an external hernia
13. CLINICAL FEATURES OF INTESTINAL
OBSTRUCTION
• Dynamic obstruction
• classic quartet of pain, distension, vomiting
and absolute constipation
14. FEATURES OF OBSTRUCTION
• high small bowel obstruction
• vomiting occurs early and is profuse
• rapid dehydration
• Distension is minimal
• little evidence of fluid levels on abdominal
radiography
15. • low small bowel obstruction
• pain is predominant with central distension
• Vomiting is delayed
• Multiple central fluid levels are seen on
radiography
16. • In large bowel obstruction
• distension is early and pronounced
• Pain is mild
• vomiting and dehydration are late
• The proximal colon and caecum are distended on
abdominal radiography
18. CLOSED-LOOP OBSTRUCTION
• obstructed at both the proximal and distal points
• no early distension of the proximal intestine
• gangrene
• retrograde thrombosis of the mesenteric veins
• malignant stricture of the right colon with a competent
ileocaecal valve
• Unrelieved, this results in necrosis and perforation
19.
20.
21. INTERNAL HERNIA
• a portion of the small intestine becomes
entrapped in one of the retroperitoneal fossae
or in a congenital mesenteric defect
• the foramen of Winslow
• a hole in the mesentery
22. • transverse mesocolon
• broad ligament
• congenital or acquired diaphragmatic hernia
• duodenal retroperitoneal fossae – left paraduodenal
and right duodenojejunal
• caecal/appendiceal retroperitoneal fossae – superior,
inferior and retrocaecal intersigmoid fossa
25. GALLSTONES
• erosion of a large gallstone through the gall
bladder into the duodenum
• 60 cm proximal to the ileocaecal valve
• recurrent attacks
• air–fluid level in the biliary tree
• The stone may not be visible
27. TRYCHOBEZOARS AND
PHYTOBEZOARS
• firm masses of hair balls and fruit/vegetable fibre
• Psychiatric abnormality
• high fibre intake, inadequate chewing, previous gastric
surgery
• hypochlorhydria and loss of the gastric pump
mechanism
29. WORMS
• Ascaris lumbricoides
• children, the institutionalised and those near the tropics
• attack frequently follows the initiation of anti-helminthic
therapy
• Debility is frequently out of proportion to that produced by
the obstruction.
• eosinophilia or the sight of worms within gas-filled small
bowel loops
30.
31. OBSTRUCTION BY ADHESIONS AND
BANDS
• Adhesions
• most common cause
• in the early postoperative period difficult to
differentiate from paralytic ileus
• peritoneal irritation results in local fibrin production
• Early fibrinous adhesions may disappear
32. CAUSES OF INTRA-ABDOMINAL
ADHESIONS
• Sites of anastomoses reperitonealisation of raw
areas trauma vascular occlusion
• Talc, starch, gauze, silk
• Peritonitis, tuberculosis
• Crohn’s disease
• Radiation enteritis
33. • Bands
• obliterated vitellointestinal duct
• a string band following previous bacterial
peritonitis
• a portion of greater omentum, usually adherent
to the parietes
34. ACUTE INTUSSUSCEPTION
• one portion of the gut becomes invaginated within an
immediately adjacent segment
• Children between 5 and 10 months of age
• 90% of cases are idiopathic
• upper respiratory tract infection or gastroenteritis may
precede
• hyperplasia of Peyer’s patches in the terminal ileum
35. • Weaning, loss of passively acquired maternal immunity and
common viral pathogens
• Meckel’s diverticulum, polyp, duplication,Henoch–Schönlein
purpura or appendix
• After the age of 2 years, a pathological lead point is found in at least
one-third of affected children
• Adult cases are invariably associated with a lead point
• polyp (e.g. Peutz–Jeghers syndrome), a submucosal lipoma or other
tumour
36. PATHOLOGY
• entering or inner tube
• the returning or middle tube
• the sheath or outer tube (intussuscipiens)
• the apex
• blood supply of the inner layer is usually impaired
• ileocolic colocolic
37.
38. CLINICAL FEATURES OF
INTUSSUSCEPTION
• episodes of screaming and drawing up of the legs
• for a few minutes and recur repeatedly
• child appears pale
• Vomiting
• blood and mucus the ‘redcurrant jelly’ stool
39. • a lump
• feeling of emptiness in the right iliac fossa (the
sign of Dance)
• apex may be palpable or even protrude from
the anus
40.
41. VOLVULUS
• twisting or axial rotation of a portion of bowel about its
mesentery
• closed loop of obstruction
• primary or secondary
• congenital malrotation of the gut, abnormal mesenteric
attachments or congenital bands
• volvulus neonatorum, caecal volvulus and sigmoid volvulus
42.
43. CLINICAL FEATURES OF VOLVULUS
• Volvulus of the small intestine
• lower ileum
• Caecal volvulus
• first the obstruction may be partial, with the passage of
flatus and faeces
• tympanic swelling in the midline or left side of the
abdomen
44. • Sigmoid volvulus
• intermittent followed by the passage of large
quantities of flatus and faeces
• Abdominal distension associated with hiccough and
retching
• vomiting occurs late
• Constipation is absolute
