Presentation on theme: "Diarrhoea Definition: Abnormal passage of loose or liquid stools more than 3 times daily and/or a volume of stool greater than 200g/day (British Society."— Presentation transcript:
Diarrhoea Definition: Abnormal passage of loose or liquid stools more than 3 times daily and/or a volume of stool greater than 200g/day (British Society of Gastroenterology) Acute diarrhoea: < 4 weeks, usually self-limiting Chronic diarrhoea: > 4 weeks
Pathophysiology 1)Increased osmotic load in the gut lumen (osmotic diarrhoea) 2) Increase in secretion (secretory diarrhoea) 3) Inflammation of the intestinal lining ie IBD 4) Increased intestinal motility Can involve more than 1 mechanism!
Infective Gastroenteritis According to Health Protection Agency and Health Protection Scotland: Most common cause: Causal agentDescription Campylobacter (46%)-transmit through raw, undercooked meat esp poultry, incubation period 2-5 days, bloody diarrhea, abdominal pain, vomiting (uncommon), possible toxic megacolon Rotavirus (19%)-most common cause of childhood diarrhoea, watery diarrhoea Norovirus (14%)-outbreaks are difficult to contain, transmit by aerosol & faecal oral,, watery diarrhoea, identify the virus doesn’t alter the management Salmonella (12%)-transmit from red and white meats, raw or undercooked eggs, milk, dairy products, or person to person. Watery diarrhoea, vomiting, fever
E.Coli (2%)-Shiga toxin producing E.coli (STEC), transmit from undercooked ground beef, water, cross contamination of cooked products,has potentially serious complication esp HUS, range from mild diarrhoea to haemorrhagic colitis, severe abdominal pain Enterotoxigenic E.coli, transmit by feacally contaminated food or water, causes watery diarrhoea Shigella (1%)-can cause bloody diarrhoea Acute dysentry = frequent, small bowel movements, accompanied by blood and mucous with tenesmus or pain on defeacation WHY? Invasive bacteria (most likely Campylobacter, Shigella, STEC) causes inflammatory invasion of colonic mucosa. Feacal leukocytes are present.
What about watery diarrhoea? - usually typical of small intestinal infection, non-inflammatory process, confirmed by absence of feacal leukocytes -mediated by bacterial endotoxins that alter fluid and electrolyte transport ie: Vibrio cholerae: transmit through contaminated water/seafood, rice water stool Cl. Difficile: usually due to antibiotics ~4-9 days (ie ampicillin, amoxicillin), varies from mild watery diarrhoea to severe bloody diarrhoea. Complications include hypovolemic shock, toxic megacolon, perforation, haemorrhage, sepsis, eradicate using metronidazole, and withdraw other antibiotics! Enterotoxigenic E.coli, Salmonella, Cryptosporidium, Cl.perfringen, Bacillus cereus, Giardia lamblia, rotavirus, norovirus
Red flag signs for Diarrhoea!!! 1)Unintentional and unexplained weight loss 2)Rectal bleeding 3)Diarrhoea persisting for more than 6 weeks, in a person over 60 years of age 4)Family history of bowel or ovarian cancer 5)Abdominal mass 6)Rectal mass 7)Anaemia 8)Raised inflammatory markers (may indicate inflammatory bowel disease).
Investigation 1) Full blood count — to detect anaemia or raised platelet count suggesting inflammation 2) Blood culture if its infective cause 3) Liver function tests, including albumin level. 4) Tests for malabsorption: Calcium. Vitamin B 12 and red blood cell folate. Iron status (ferritin). 5) Thyroid function tests. 6) ESR & CRP — elevated levels may indicate IBD 7) Antibody testing for coeliac disease — immunoglobulin (Ig)A tissue transglutaminase antibody (tTGA), or IgA endomysial antibody (EMA).
Investigation Consider sending stool for culture and sensitivity and examination for ova, cysts and parasites, if an infectious cause is suspected or there is a history of travel to high-risk areas. Send three specimens (5 mL each) 2–3 days apart, as ova, cysts, and parasites are shed intermittently.
Management Treat the cause! 1)Oral rehydration (better than IV), if impossible give 0.9% saline + 20 mmol K+/L IVI 2)Codeine phosphate 30mg/6 hrs 3)Loperamide 2mg PO 4)Avoid antibiotics except in infective diarrhoea causing systemic illness
Definition of constipation: = difficult or infrequent passage of stool ( <3x a week), hardness of stool, or a feeling of incomplete evacuation. Absolute constipation: Failure to pass any stools.
Types of constipation: 1) Functional/primary/idiopathic constipation =chronic constipation without a known cause 2) Secondary/organic constipation - caused by medical conditions or drugs ie opioids, TCA, antispasmodic, calcium supplement, aluminium antacids 3) Faecal loading/impaction 4) Overflow incontinence/ bypass soiling/encopresis leakage of loose stool around impacted faeces.
Pathophysiology 1)Colonic inertia (reduced bowel movement) 2)Outlet delay constipation (or obstructed defecation) which can be caused by pelvic floor dyssynergia (the pelvic floor muscles contract or fail to relax during attempted defecation), and by anismus (the external anal sphincter contracts instead of relaxing during attempted defecation
Causes of Constipation Acute constipation Bowel obstruction Volvulus, hernia, adhesions, fecal impaction Adynamic ileusPeritonitis, major acute illness (eg, sepsis), head or spinal trauma Drugs Anticholinergics (eg, antihistamines, antipsychotics, antiparkinsonian drugs, antispasmodics), cations (iron, aluminum, Ca, barium, bismuth), opioids, Ca channel blockers, general anesthesia
Predisposing factors 1)Social factors: Low fibre diet 2)Lifestyle: Difficult access to toilet, or changes in routine/lifestyle, Lack of exercise; reduced mobility. 3)Psychological: Anxiety, Depression, Somatization, Eating disorders 4)Physical: Mild pyrexia, dehydration, immobility.
RED FLAGS FOR CONSTIPATION! 1)Persistent unexplained change in bowel habits? 2)Palpable mass 3)Persistent rectal bleeding without anal symptoms 4)Distended, tympanitic abdomen 5)Vomiting 6)Family history of colon cancer, IBD 7)Unexplained weight loss, iron deficiency anaemia, fever, or nocturnal symptoms 8)Severe, persistent constipation that is unresponsive to treatment
How to interpret clinical findings: 1)Abdominal pain 2)Vomiting 3)Abdominal distention 4)Progress of condition 5)Sigmoid volvolus 6)Ischemia/perforation 7)Pseudo obstruction
How to interpret clinical findings: How to differentiate Intestinal Obstruction & paralytic Ileus ? IO – partial active, tinkling bowel sounds complete absent bowel sounds & absent flatus, usually severe vomiting PI – absent bowel sounds & flatus is present SO? Radiology!
Small bowel obstruction Gallstone ileus -multiple dilated small bowel Throughout SMALL ALL ->3cm is abnormal -valvulae conniventes -paucity of gas in bowel beyond site of obstruction
Paralytic ileus White arrow – multiple dilated small bowel loops Black arrow- surgical staples
To differentiate small bowel obstruction and paralytic ileus CT scan to exclude any obstruction, if there’s no obstruction, check medical history: ie previous surgery or electrolyte imbalance such as hypo/hyperkalemia, hypocalcemia, hypomagnesemia indicates paralytic ileus
Large Bowel Obstruction Colon Ca -dilated bowel loops proximal to obstruction -dilated large bowel loop >6cm
Investigations Depends on clinical findings: 1)Constipation with a clear etiology (drugs, trauma) may be treated symptomatically without further study. 2)Blood tests: FBC, U&E, Ca2+, TFT If suspected malignancy, proceed with: 4)Abdominal X-ray 5)Sigmoidoscopy and biopsy of abnormal mucosa 6)Colonoscopy 7)Water soluble contrast enema 8)CT Scan or barium X-ray
Management 1)Adjust any constipating medication, if possible. 2)Increasing dietary fibre, drinking an adequate fluid intake, and exercisedietary fibre 3)Offer oral laxatives if dietary measures are ineffective, or while waiting for them to take effect. 1)Bulk-forming laxative ie ispaghula husk, methylcellulose, sterculia, frangula 2)Osmotic laxative ie lactulose, macrogols (polyethylene glycols) 3) Stimulant laxative ie bisacodyl, senna, sodium picosulfate Laxatives can be stopped once the stools become soft and easily passed again
Questions 1)A 20 year old girl presents with abdominal pain and recently up to 15 bouts of diarrhoea containing blood and mucus. Her stool culture is negative IBD 2)A 23 year old medical student is on elective in Thailand, when he develops cramping abdominal pain and a watery diarrhoea after drinking the local water. It is self limiting and resolves after few days Entero E.coli 3)A 36 year old woman presents with weight loss, general abdominal discomfort and steatorrhoea. On examination she appears pale and malnourished. Gastric ca 4)A 36 year old woman presents with abdominal pain and an acute watery diarrhoea containing blood. She has no significant PMH apart from a recent pneumonia which was treated with amoxicillin Cl.difficile A: chronic gastritis B: Cl. Difficile infection C: IBD D: gastric ca E: Enterotoxigenic E.coli F: ischaemic colitis G: Colorectal Ca H: Cholera