Week 5 Flashcards
What is the definition of diarrhoea?
loss of fluid and solutions from the GI tract in excess of 500ml per day
List some causes of diarrhoea
Infection - viral/bacterial/parasites IBD IBS Excess bile salts Hyperthyroidism Drugs
What can use of broad spectrum antibiotics cause the development of?
Clostridium Difficile Colitis
What are some of the adverse effects diarrhoea has on the body?
Dehydration
Hypokalaemia
Metabolic acidosis
What percentage of body weight contitutes severe fluid loss?
> 10%
What are the three classes of drugs/ management used for the treatment of diarrhoea?
Rehydration supplements
Antimicrobials
Anti-motility agents
What are some of the causes of constipation?
Lack of exercise
Suppressing the urge to defecate
Decreased colonic motility - age, metabolic disorders e.t.c
Which two drug classes are used to manage constipation?
Laxatives
Purgatives
What are the 4 main classes of laxatives and purgatives and which is the most commonly used?
BULK LAXATIVES (most commonly used)
OMOTIC LAXATIVES
STIMULANT PURGATIVES
FAECAL SOFTENERS
What are some of the clinical indications of laxatives?
Straining with constipation Painful defecation Bedridden patients For expulsion of parasites To prepare the GI tract before surgery e.t.c
If acute travellers diarrhoea occurs after the patient has spent time on a cruise ship, what should be suspected?
Norovirus and Rotavirus
How does cholera present?
Profuse watery diarrhoea
What can be given as a single dose for 3 days for people who are travelling to prevent worsening of diarrhoea?
Fluoroquinolone / Ciprofloxacin
What is enteric fever?
A food born illness which includes typhoid and paratyphoid fever
Does enteric fever have a long or short incubation period?
Quite long (7-18 days - can be up to 60)
Which type of jaundice is associated with HUS as a complication?
Pre-hepatic (haemolytic)
What are the genetic associations of IBD?
NOD2
HLADR1
In terms of IBD, which disease is TH1 mediated and which is TH1/ TH2 mediated?
Crohn’s - TH1 mediated
Ulcerative Colitis - TH1/ TH2 mediated
Which inflammatory bowel disease is aggravated by smoking?
Crohn’s Disease
Which drug class can aggravate inflammatory bowel disease and should be avoided if possible?
NSAIDs
Where in the GI tract does Crohn’s disease affect?
Anywhere from mouth to anus, most commonly in the terminal ileum and proximal colon
Where in the GI tract does ulcerative colitis affect?
Colon and rectum
Which inflammatory bowel disease can be described as being patchy with skip lesions?
Crohn’s Disease
Which kind of inflammation does Crohn’s disease involve and which kind does ulcerative colitis involve (in terms of layers of the GI tract wall affected)
Crohn’s = transmural inflammation
Ulcerative Colitis = Inflammation of the mucosa and submucosa
Which inflammatory bowel disease is continuous?
Ulcerative Colitis
Which inflammatory bowel disease involves; granulomas and a thickened bowel and strictures?
Crohn’s disease
In which IBD are fistulas most common?
Crohn’s disease
Which IBD has the highest risk of cancer?
Ulcerative colitis
What are some of the complications of IBD? List 3!
Fistulas
Toxic megacolon
Cancer (colorectal)
What are some of the extra intestinal associations of IBD?
Mouth ulcers Swollen lips Angular cheillitis Clubbing Erythema nodosum Pyoderma Gangrenosum Arthritis
Ulcerative Colitis is named depending on how much of the GI tract it affects, name the 3 possibilities from smallest to largest
Proctitis, Left-sided colitis, Pancolitis
What investigations would be done for IBD?
History and clinical examination
Bloods (CPR and Albumin)
Endoscopy and Colonoscopy + mucosal biopsy
Small bowel MRI (crohn’s) / plain AXR (Ulcerative Colitis)
Barium swallow (crohn’s)
What are the 4 classes of drugs used to treat IBD and which of these is mainly only used in Ulcerative Colitis?
5 ASA (ulcerative colitis)
Steroids
Immunosuppressants
Anti- TNFa
Suppositories and Enemas are used for topical therapy of 5ASA in IBD, What is the difference between these and which has better adherence to mucosal surfaces?
Suppositories = solid (better adherence) Enemas = liquid
What is a possible side effect of 5 ASA?
Nephritis (Renal function should therefore be monitored)
Which steroids are used to treat IBD?
Prednisolone!
Budesonide
What are some of the side effects of steroids?
Oseteoporosis Acne Thinning of the skin Weight gain Diabetes
Name an immunosuppressant drug used for the treatment of IBD?
Azathioprine
How does the active form of azathioprine work?
It affects DNA synthesis, inhibiting T cell proliferation in inflammation
What are some of the side effects of immunosuppressant drugs?
Pancreatitis Hepatitis Leucopaenia Hepatitis Lymphoma/ Skin cancer
In azathioprine metabolism, 6-MP can accumulate in toxic concentrations, what enzyme converts this substance in to a non-toxic form?
TPMT
How does anti- TNF therapy for IBD work?
It promotes apoptosis of activated T-lymphocytes
Name an Anti-TNF drug used in the treatment of IBD
Infliximab
What are the side-effects of anti-TNF therapy?
Infection (TB!)
Cancer
Which form of IBD can be cured by surgery?
Ulcerative Colitis
What is meant by a colectomy?
Permanently removing the colon
There are two options for finishing a colectomy operation for allowing passage of faeces out of the body, what are these?
Ileostomy - the S.I is diverted out of a hole in the abdomen and a stoma bag is attached
Ileo-Anal Pouch - Part of the S.I is used to create an internal pouch which is attached to the anus
In a subtotal colectomy for emergency ulcerative colitis surgery, what two different things can be done with the rectum?
The rectum can be left in the body and stable off
The rectum can be left as a mucous fistula
What are some of the complications of an Ileo-anal pouch?
Infertility
Pouchitis
Ileus
Haemorrhage
What are some of the indications for surgery for IBD?
Failed medical therapy Dysplasia/ malignancy Perforation Toxic megacolon Abscesses Fistulas
What kinds of surgery can be done for crohn’s disease?
Resection of the worst areas
Temporary Ileostomy
What does diarrhoea caused by staph aureus involve?
Onset 1-6 hours after exposure, with diarrhoea lasting 6-10 hours.
Afebrile
Abdominal Pain
Diarrhoea (but no blood or mucus)
Which organism is the common cause of traveller’s diarrhoea?
ETEC (Enterotoxigenic E.coli)
What symptoms does infection with E.coli 0157 cause?
Crampy abdominal pain
Diarrhoea + lots of blood
Little/ no fever
What changes occur in HUS?
Renal injury
Thrombocytopaenia - haemolytic anaemia
What is a rare but important complication of campylobacter not to forget about?
Guillain- Barre syndrome
What does ‘thumb printing colitis’ in radiography indicate?
Mucosal oedema and inflammation as a consequence of diarrhoea
What are the symptoms of enteric fever/ typhoid?
Fever
Abdominal pain
Constipation
Diarrhoea
What can cause clostridium difficile infection and what kind of organism is it?
Use of broad spectrum antibiotics (kills of normal microbe in the GI tract)
C.diff = an anaerobic gram +ve and spore bearing bacillus
What is amoebiasis?
A tropical infection cause by a protozoa (Entamoebe histolytica)
How would an amoebic liver abscess present?
Fever
Upper abdominal pain
Hepatomegaly
What is giardiasis?
A tropical infection caused by a protozoa (Giardia intestinalis )
List some ways that infections can be transmitted during sex
Contact with secretions
Fomites (sex toys)
Drug use during sex
How are gonorrhoea and chlamydia passed on and how do they differ?
Transmission of both is by direct contact with mucosal surfaces
Gonorrhoea can have more serious symptoms E.g ; abdominal pain, rectal bleeding and tenesmus
What organism is characteristic of gonorrhoea?
Gram -ve diplococci
Why are patients with gonorrhoea at a higher risk of catching HIV?
Because gonorrhoea involves inflammation and thus there are many CD4 receptors for the HIV virus
Which are the bacterial causes of STIs and which are the viral causes?
BACTERIAL - Gonorrhoea - Chlamydia - Syphilis VIRAL - Herpes simplex virus - HIV - Human papilloma Virus
How does primary syphilis present and how does secondary syphilis present?
Primary - painless ulcer
Secondary - Systemic inflammatory response
What is conchylomata lata and which STI is it associated with?
Wart like lesions, associated with syphilis
What is lymphomagranuloma and which groups of patients is it associated with?
Inguinal lymphadenopathy and ulceration Patients; HIV Syphilis Hep C Men who have sex with men
Why does HIV drastically affect the gut?
The gut is the major immune component in the body
Which cancer is the second most common cause of death in the UK?
Colorectal
Which genes can be mutated, leading to development of colorectal cancer?
APC KRAS p53 18q (Tumour suppressor genes and oncogenes)
Where is common site of metastasis from a colorectal cancer?
The liver, due to the blood supply draining here for cleaning
What are some protective and causative lifestyle factors of colorectal cancer?
PROTECTIVE Exercise Vegetables and fibre CAUSATIVE Obesity Red and processed meat Smoking and alcohol
What are two forms of autosomal dominant inheritance of colorectal cancers?
FAP
HNPCC
What are some o the clinical features of colorectal cancer?
Anaemia Cachexia Lymphadenopathy Hepatomegaly Abdominal distension Abdominal mass PR bleeding Rectal mass
What are the investigations for colorectal cancer?
Barium enema CT colonography Sigmoidoscopy and colonoscopy FOBT (screening test) CT of lungs and liver for metastasis MRI (for staging)
What might the emergency presentation of colorectal cancer involve?
Bleeding
Perforation
Obstruction - distension, constipation, ab pain, vomting
How is colorectal cancer treated?
Surgery
Radiotherapy
Chemotherapy
What is meant by acute gastroenteritis?
Inflammation of the lining of the stomach, small intestine or large intestine
What is a severe and worrying complication of intestinal bacterial enteritis?
Severe dehydration and renal failure
What is the major cause of diarrhoea and colitis in patients who have been exposed to antibiotics?
Clostridium Difficile
How can acute travellers diarrhoea be defined?
3 loose stool in 24 hours + self-reported fever
List 4 things which could be possibilities in a differential diagnosis of a change in bowel habit
IBS
IBD
Infective gastroenteritis
Bowel cancer
List some ‘types’ of diarrhoea
Secretory
Inflammatory
Dysentery
How is constipation defined?
Infrequent bowel movements, difficulty or straining during defecation and hard stools
What signs of coeliac disease can be found from outwith the GI tract?
Anaemia
Itchy rash
Aphthous ulcers
Angular stomatitis
