Bowel Obstructoni Flashcards
What is small bowel obstruction (SBO)?
A surgical emergency characterized by abdominal pain, vomiting, and abdominal distention that disrupts intestinal flow.
What are the types of small bowel obstructions?
Simple obstructions with mechanical blockage which may be a gallstone ileus (At ileocaecal valve))intramural lesion
extrinsic adhesion, causing proximal bowel distention and distal bowel decompression which increases intraluminal pressure alternative causes include volvulus, strictures and tumours.
What are the common causes of small bowel obstruction?
Common causes include:
* Post-operative adhesions: MOST COMMON
* Gallstone ileus
* Intramural lesions
* Extrinsic adhesions
* Malignanc
* Volvulus
* Strictures
* Tumors
What is a simple obstruction?
A mechanical blockage causing proximal bowel distention and distal bowel decompression.
What characterizes functional obstruction?
Peristalsis disruption due to metabolic disturbances, neural inhibition, or inflammation.
What is a strangulated obstruction?
An obstruction where blood flow is compromised, leading to bowel ischaemia.
List some conditions that can cause small bowel obstruction.
- Hernia
- Malignancy (e.g., carcinoid, adenocarcinoma)
- Inflammation (e.g., Crohn’s disease)
- Endometriosis
- Reduced intestinal motility
Why is SBO more common in older adults?
Due to higher risk factors such as abdominal surgery, malignancy, and hernia.
What are the systemic effects of prolonged ischaemia in SBO?
Can lead to necrosis of the bowel wall, liquefactive necrosis, and vascular thrombosis in the mesenteric vein.
What are the clinical presentations of SBO?
Acute abdominal pain, vomiting, dehydration, abdominal distention, tenderness over the obstruction site.
What diagnostic tests are used for SBO?
- FBC for leukocytosis
- Electrolyte assessment
- ABG for metabolic alkalosis or lactic acidosis
- Amylase levels
- Blood cultures
- Upright chest radiograph
- CT scan (gold standard)
What treatment is indicated for SBO?
Fluid resuscitation, broad-spectrum antibiotics, and surgical intervention for strangulated cases.
What are the complications of SBO?
- Bowel ischaemia
- Perforation
- Further adhesion formation
- Malnutrition
- Peritonitis
What is a common cause of large bowel obstruction?
Cancers, inflammation, or mechanical obstructions in the colon.
What benign causes can lead to large bowel obstruction?
- Volvulus of sigmoid colon
- Diverticular disease
- Food blockages
- Foreign body
- Inflammation from IBD
What are the clinical features of large bowel obstruction?
Pain, abdominal distention, absent bowel movements, nausea, and vomiting.
What does the pathophysiology of large bowel obstruction involve?
Exacerbation by gas-forming bacteria, reduced venous outflow, ischaemia, necrosis, and perforation.
What are the diagnostic methods for lower bowel obstruction?
- FBC for anemia and infection markers
- Blood culture/stool for C. diff
- Upright chest x-ray
- CT imaging
How is a benign obstruction typically treated?
Balloon dilatation via endoscopy.
What risks are associated with the use of stents for obstruction?
- Perforation
- Dissemination of malignancy
What immediate action should be taken for perforation in bowel obstruction?
Treat immediately due to the risk of widespread faecal contamination and sepsis.
What is pseudo-obstruction?
Occurs with excessive sympathetic stimulation in the colon, decreasing colon motility.
What is the typical presentation of colorectal malignancy?
Progressive change in bowel habits, alternating between diarrhea and constipation, with possible rectal bleeding and weight loss.
