Lower GI diseases (medicine) Flashcards
Coeliac Disease
inflammation of the mucosa of the upper small bowel when exposed to gluten
In people with coeliac disease, proteins in gluten containing foods are resistant to digestion by ———— and remain in the intestinal lumen, triggering ———-
digestion by pepsin & chymotrypsin
triggering immune responses
In coeliac disease, immune response causes inflammation, which leads to ———–
villous atrophy and crypt hyperplasia; this in turn leads to malabsorption of other nutrients
Coeliac disease affects about —–% of the population
1%
Coeliac disease can present at any age. True/false?
True.
Coeliac disease - associated Diseases (other autoimmune diseases)
Thyroid disease Type 1 diabetes Sjogren Syndrome IBD IgA deficiency
Coeliac disease - signs/symptoms
Abdo pain Weight loss (failure to thrive in kids) Diarrhoea/steatorrhea Angular stomatitis on corners of mouth Dermatitis herpetiformis on extensor surface of elbows Anaemia, malnutrition
What are the long-term problems associated with coeliac disease?
iron/folate deficiency
osteoporosis
Coeliac disease - investigations
1st line = serology tTG antibodies (IgA tissue transglutaminase antibodies) EMA (IgA endomysial antibodies)
2nd line = biopsy
Other blood tests e.g. iron and folate def.
DEXA scan to check bone density
Coeliac disease - management
Gluten-free diet Vitamin supplements Pneumococcal vaccines for pts with splenic atrophy Annual blood tests (serology and FBC) Screen for other autoimmune conditions
Coeliac disease - differential
IBS
IBD
GI Malabsorption
Defective mucosal absorption. The digestive system does not have the function and/or enzymes to break down the substances from the diet.
GI Malabsorption - common causes
Coeliac, Lactose intolerance, Crohn’s, post infective, chronic pancreatitis, Biliary obstruction, liver cirrhosis
GI Malabsorption - rarer causes
Whipple’s disease, drugs, PSC, short bowel
Whipple’s disease
A multisystem bacterial infection that mainly affects the digestive system and joints. Leads to impaired breakdown of nutrients and malabsorption.
GI Malabsorption
Diarrhoea, weight loss, bloating, abdo pain.
Signs: Anaemia, oedema, steatorrhea, bleeding disorders, neuropathy.
Lactose intolerance is an allergic reaction. True/false?
False.
Intolerance is different to allergy
How is lactose malabsorption different to an allergy?
Lactose intolerance = patient produces little/no lactase»_space; will not break down lactose into glucose/galactose»_space; undigested molecule will cause digestive problems e.g. diarrhoea, abdominal pain.
Allergy = mediated by the immune system, commonly involving IgE antibodies. (rashes, swelling, hives, wheezing)
Tropical sprue
A rare digestive disease of unknown cause that affects the small bowel’s ability to absorb nutrients. Especially vitamin B12 and folic acid.
Tropical sprue leads to hypertrophy of villi of digestive wall. True/false?
False.
Atrophy of villi.
Tropical sprue - symptoms
Fatigue, diarrhoea, anorexia
Vitamin C deficiency
Scurvy.
Symptoms/ signs: gum disease, anorexia, weakness.
Vitamin D deficiency
Osteomalacia, rickets
Scurvy is caused by vitamin D deficiency. True/false?
False.
Vitamin C deficiency
Malnutrition
State of nutrition in which a deficiency or imbalance of energy and nutrients leads to adverse effects on body tissue, function and clinical outcome.
Malnutrition - treatment
Food first
Oral supplements
Enteral Feeding Tube = into stomach or small intestines by tube
Parenteral nutrition = via a central or peripheral vein
Small bowel tumours
3 types =
Adenocarcinoma
Lymphoma
Carcinoid tumours
In the small bowel, primary tumours are common; secondary tumours are much more rare. True/false?
False
Primary tumours are rare, secondary tumours are much more common.
Crohn’s is a predisposing factor to which cancer?
Adenocarcinoma of the small bowel
Small bowel adenocarcinomas are most commonly found in ————–
Lymphomas are most commonly found in ————-
Adenocarcinomas = duodenum, jejunum Lymphomas = ileum
The most common small bowel lymphoma is T cell arising from MALT. True/false?
False.
B cell arising from MALT.
Adenocarcinomas are the most common tumour found in the small bowel. True/false?
True
Adenocarcinomas and Lymphomas of the small bowel are managed with chemo/radio. True/false?
False.
SURGICAL RESECTION + chemo/radio
Carcinoid tumours are a type of fast-growing neuroendocrine tumour. True/false?
False.
Slow-growing neuroendocrine tumour
Carcinoid tumours originate from ———- cells of the intestine.
enterochromaffin
In the small bowel, carcinoid tumours are most commonly found in ———–
appendix and terminal ileum
Carcinoid syndrome tends to occur only if ———-
the tumour has metastasised
commonly to liver
A key substance that is overproduced by carcinoid tumours is ————-
serotonin
increases motility and peristalsis, bronchoconstriction and can produce collagen via fibroblasts in the heart
Carcinoid syndrome - symptoms
Spontaneous flushing
Diarrhoea
Shortness of breath/wheezing
Pulmonary stenosis or tricuspid incompetence
Carcinoid tumours usually cause symptoms e.g. diarrhoea, shortness of breath, tricuspid regurg etc. True/false?
False.
Most carcinoid tumours are asymptomatic.
These are symptoms of carcinoid syndrome.
Carcinoid tumour - investigations
Serum chromogranin A
24hr urine secretion of 5-hydroxyindoleacetic acid
(imaging to check for mets)
Carcinoid tumour - treatment
Surgical resection
Octreotide/lanreotide (somatostatin analogues) inhibit the release of hormones, alleviating symptoms
Irritable Bowel Syndrome (IBS) is a functional bowel disorder in which abdominal pain is associated with structural pathology and a change in bowel habit. True/false?
False.
Abdominal pain is associated with change in bowel habit in the ABSENCE of structural pathology
IBS is associated with which other non-GI related medical conditions?
anxiety/stress/depression
IBS is more common in men. True/false?
False.
more common in women
What examinations would you conduct for suspected IBS?
Check BMI for unexplained weight loss
Abdo exam to check for tenderness/masses
PR exam to check for rectal pathology
Which conditions should be ruled out in the diagnosis of IBS?
IBD and coeliac
IBS - investigations
FBC - anaemia, raised platelets (may suggest inflam)
ESR/CRP - raised in infection/inflam
Coeliac serology
If the patient reports >6 months of abdo discomfort with ———- they can be diagnosed with IBS
Improvement with defecation/
change in frequency of stool/
change in appearance of stool
IBS - management
Identify dietary/mental triggers
Dietary advice
Recommend increased probiotic intake
Consider anti-diarrhoeals (e.g. loperamide)
Consider laxatives
Antispasmodics if abdo pain not resolving
Inflammatory Bowel Disease (IBD) has 2 types =
Crohn’s Disease (CD) Ulcerative Colitis (UC)
IBD - environmental triggers
Smoking, NSAID use, hygiene, diet and nutrition, stress.
Crohn’s disease only affects the colon. True/false?
False.
CD affects any part of the GI tract
UC only affects the colon
There is evidence of altered bacteria flora in IBD. True/false?
True
IBD occurs due to ———–
an overactive mucosal immunological response to luminal antigens e.g. bacteria
IBD patients have leaky epithelium which increases chance of detection of antigen by immune cells. True/false?
True
How is the T cell response altered in IBD?
Overactive effector T cell response
An absence of regulatory T cells
What T cells mediate:
Crohn’s?
UC?
Crohn’s - TH1 mediated
UC - mixed Th1/Th2
IBD increases the risk of developing ———–
Colon cancer
Toxic megacolon (in UC)
Bowel obstruction
Sclerosing cholangitis
Eye manifestations of IBD
uveitis, episcleritis, conjunctivitis
Skin manifestations of IBD
erythema nodosum, pyoderma gangrenosum
Joint manifestations of IBD
arthralgia, ankylosing spondylitis
Liver and biliary tree manifestations of IBD
sclerosing cholangitis, fatty liver, chronic hepatitis, cirrhosis, gallstones
Crohn’s Disease
Autoimmune inflammatory disorder that involves the entire GI tract.
(terminal ileus most commonly affected)
Crohn’s disease - signs/symptoms
Abdominal Pain- depends on site of inflammation Diarrhoea (rarely blood or mucus) Weight loss/reduced growth in children Fatigue Malaise Fever Mouth ulcers Angular stomatitis