Bowel Conditions Flashcards
What is intestinal failure?
Inability to maintain adequate nutrition or fluid status via the intestines.
What causes intestinal failure?
Obstruction, dysmotility, surgical resection, congenital defect, or disease associated loss of absorption
Of the 3 types of intestinal failure, which are acute and which are chronic?
Type I & II IF are acute. Type III IF is chronic
Describe Type 1 IF
Self limiting short term postoperative or paralytic ileus
Describe Type II IF
Prolonged, associated with sepsis and metabolic complications. Often related to abdomen surgery with complications
Describe Type III IF
Long term but stable - home parenteral nutrition often indicated. e.g. short gut syndrome
What is the management of Type I IF?
- Replace fluids/electrolyes through IVs
- Parenteral nutrition if can’t tolerate food/fluids > 7 days post op
- Acid suppression (PPIs)
- Octreotide (minimises movement and secretion of gut)
What is parenteral nutrition?
Also known as intravenous feeding, is a method of getting nutrition into the body through the veins
What are the main complications of parenteral feeding?
Pneumothorax, arterial puncture, misplacement, sepsis
What are some of the causes of Type II IF?
• Surgical complications • Coeliac disease • Vascular ischaemia • Crohn’s • Malignancy • Radiation
What is the management for Type III IF?
- Home parenteral nutrition - Intestinal transplantation Newer methods: - GLP2 treatment for short bowel syndrome - Bowel lengthening (regrowing lost bowel)
What is the length criteria for short bowel syndrome?
250-850cm
What is the 5 year survival for HPN vs intestinal transplant?
HPN: 70% 5year survival Intestinal Transplant: 50-60% 5y survival (eating but also requires stoma)
What is the main priority with IF?
Look for and address malnutrition
Where does the vasculature supply for small bowel come through?
The mesentery
What are the histological characteristic of small intestine?
Villi (which are lined by enterocytes and goblet cells full of mucin). Enterocytes are lined with brush border with microvilli
What does the jejunum have that the ileum doesnt?
Jejunum has a ‘stack of coins’ appearance because of plicae circularis (mucosal folds) while ileum is ‘characterless’, and appears a cylindrical tube
What are the 2 main mechanisms behind ischeamia of the small bowel and give examples of each
1) Mesenteric arterial occlusion (e.g. atherosclerosis of SMA or thromoelbolism from AF) 2) Non occlusive perfusion insufficiency (e.g. shock, strangulation obstructing venous return, drugs, hypervoscity)
What is the classification of small bowel ischaemia based on?
Degree of infarction caused i.e. mucosal to transmural
What is Meckel’s Diverticulum?
Result of incomplete regression of vitello-intestinal duct where used to get nutrients from the yolk sac (outppuch structure of the small bowel)
Why is Meckel’s a disease of 2s?
-Pts present around the age of 2 - It is 2 inches long - 2 feet above the IC valve - Affects 2% if the population
Which condition can Meckel’s mimic if it become diverticulitis?
Appendicitis
True or False: Primary tumours of the small bowel are more common than secondary tumours
False, secondary tumours are much more common, such as from ovary, colon and stomach
What are the 3 main primary tumours of the small bowel?
1) Lymphomas (mostly Maltomas) 2) Carcinoid tumours 3) Carcinomas
What is the commonest site for carcinoid tumours of the small bowel?
Appendix
What is carcinoid syndrome and when does it often occur?
Often occurs when carcinoid tumours spread to the liver and hormones such as serotonin are released into the bloodstream, and involves a collection of symptoms: -diarrhoea, abd. pain and loss of appetite - flushing of the skin, particularly the face - fast HR - SOB and wheezing
What are carcinoid tumours?
Tumours of the endocrine system
Which disease are associated with carcinoma of the small bowel?
Crohn’s and coeliac
What are the histological characteristics of carcinoid tumours?
They produce these islands of cells which are homogenous/monotonous throughout
What is the commonest cause of an acute abdomen?
Appendicitis
What are the signs and symptoms of appendicitis?
Vomiting, abdominal pain, RIF tenderness and increased WCC
What are the main causes of appendicitis?
- Unknown - Faecoliths (dehydration) • Impacted faeces - Lymphoid hyperplasia - Parasites - Tumours (rare)
What are the histological findings of appendicitis?
Muscosal ulceration and mural inflammation, and pus/neutrophils in lumen
What are the complications of appendicitis?
- Peritonitis - Rupture - Abscess - Fistula - Sepsis
What is the underlying pathophysiology of Coeliac Disease?
An abnormal reaction to gliadin, a constituent of wheat flour, gluten, which damages enterocytes and reduces absorptive capacity (essentially an auto-immune disease)
What is coeliac disease strongly associated with?
- HLA-B8 haplotype (gene thingy) - Dermatitis herpetiformis - Strong association with childhood diabetes
What happens to gliadin, the toxic gluten component, in Coeliac disease?
Gliadan, instead of being broken down as normal, start an auto-immune inflammatory response
Which cells mediated the inflammatory response in Coeliac disease?
T-cell lymphocytes which exist within the small intestinal epithelium ‘intraepithelial lymphocytes’ (IELS)
What is seen histologically in Coeliac disease?
- There is increasing loss of enterocytes leading to loss of villous structure, loss of surface area, a reduction in absorbtion and a flat duodenal mucosa - No villi, only crypts as it is all flat - On surface can also see lots of lymphocytes and inflammation in lamina propria - Stem cells cant keep up with the regeneration so becomes flat - Also massive infiltrate of toxic t cells
What is the most sensitive test for coeliac disease and what are the positive findings?
Serology: Antibodies anti-TTG, anti-endomesial, anti-gliadin
What are the symptoms of malabsorption?
• Loss of weight • Anaemia (Fe, Vit B12, Folate) • Abdominal bloating • Failure to thrive • Vitamin deficiencies
What are the complications of Coeliac disease?
- Malabsorption
- T-cell lymphomas of GI tract
- Occurs because the t cells have become autonomous and have the inflammatory effect even without the gluten trigger
- Increased risk of small bowel carcinoma
- Gall stones
- Ulcerative-jejenoilleitis
What does the clinical features of small bowel obstruction depend on and what are they?
Depends on the level obstruction Proximal: vomiting, no distension Dista: late vomiting, gross distension
What are the 2 main types of small bowel obstruction?
• Mechanical • Adynamic (ileus) (Essentially stops functioning)
What are the mechanical causes of small bowel obstruction divided into?
- Intraluminal (in lumen) (e.g. Tumour, Gall stone ileus)
- Intramural (in wall) (e.g.Crohn’s)
- Extrinsic compression (e.g. Adhesions, Hernia, Volvulus)
What are the overall causes of any bowel obstruction
B - bolus
A - adhesions (congenital or surgical)
T - tumour
H - hernia
V - volvulus
I - ileus/inflammatory/intussusception
P - pseudo-obstruction
S - strictures
What are the main investigations for diagnosis small bowel obstruction?
- AXR (erect if possible) -CT
What is the management of small bowel obstruction?
Generally conservative without surgery:
- Fluid resuscitation potassium as fluid is pooling in bowel and usually hypokalaemic
- Analgesia
- Catheterise
- NG tube (to decompress stomach)
- Antithrombolitics (high risk of DVT)
- Operate if there is a risk of hernia, cancer or strangulation
What is the cause of mesenteric ischaemia?
Embolus or thrombosis (arterial and venous)
What condition is ‘angina of the gut’ referring to?
Chronic mesenteric ischaemia - often due to atherosclerosis in the SMA
What us the investigation of choice for mesenteric ischaemia?
CT
As well as pancreatitis, which condition can cause a raised amylase?
Small bowel ischaemia
Is Meckel’s diverticulum a true or a false diverticulum?
True
What is the clinical presentation of Meckel’s?
Often asymptomatic In children it may cause: - Rectal bleeding, obstruction and perforation
What is the road bump sign?
When you ask what brough them in or if anything bothered them on the way in, they will often say the road bumps
What are the clinical features of appendicitis both initially and progressively?
Initial visceral: - Nausea - Anorexia - Central abdominal pain Progressive parietal: - Right iliac fossa pain - Puritanism
What is the main investigation for carcinoid tumour of the appendix?
Chromafrannin A staining
What is diverticular disease?
Protrusion of a cavity through its contents, such as like a hernia
What is the difference between a true and false diverticulum?
- True diverticulum – all the layers - False diverticulum – just the mucosa comes through
What would you use to diagnose diverticular disease?
- Barium enema -Colonoscopy/sigmoidoscopy
What are the clinical features of diverticulitis?
• LIF pain/tendernss • Altered bowel habit • Septic (palpitations, fever, lethargy, anorexia)
What are the complications of diverticulitis?
• Pericolic abscess – infection gets walled off • True perforation • Lumen haemorrhage • Stricture • Fistula
How would you class acute diverticulitis?
Hinchey classification
How would you treat uncomplicated diverticulitis?
Oral antibiotics (if anything)
How would you treat complicated diverticulitis?
- Hartmen’s procedure (Remove the sigmoid colon and leave with an end colostomy )
- Primary resection/anastomosis
- Percutaneous drainage
- Laparoscopic lavage and drainage
What are the causes of colitis?
- IBD (Crohn’s disease and ulcerative colitis)
- Bacterial infections (campalo bacter, shigaella, e. coli, C. difficile -causes pseudomembranous colitis)
- Ischaemic colitis due to chronic vascular insufficiency
What are the symptoms of colitis?
- Diarrhoea +/- blood
- Abdominal cramps
- Dehydration (due to diarrhoea)
- Sepsis
- Weight loss or anaemia
How would you diagnose colitis?
- Xray - lead piping (loss of mucosal folds), thumb printing, toxic colon
- Sigmoidoscopy and biopsy
- Stool cultures (rule out infective colitis)