Gastrointestinal conditions Signs, causes And Differentials Flashcards
What are the causes of metabolic acidosis?
Diabetic ketoacidosis (ketones produced are acidic)
Lactic acidosis (increased acid production)
Renal failure (reduced acid secretion)
Chronic diarrhoea (bicarbonate loss)
What are the causes of metabolic alkalosis?
Increased alkali ingestion
Vomiting
Potassium depletion
What is irritable bowel syndrome?
What are the subtypes?
A chronic condition primarily manifesting as a syndrome of colicky abdominal pain, bloating and altered bowel habit.
Types:
Diarrhoea predominant
Constipation predominant
What are the signs of irritable bowel syndrome?
Presentation is variable
- Colicky abdominal pain anywhere in abdomen, can be severe pain
(colic = pain that abruptly comes and goes with peristaltic motions) - Abdominal bloating
- Constipation, diarrhoea or alternating between the two
- Faecal incontinence
- Urgency
- Exaggerated gastro-colonic reflex (every time you eat, you defaecate)
- Anxiety about eating
- Bloating (can go up 2 dress sizes)
Extra-intestinal symptoms:
- Nausea
- Thigh pain
- Back ache
- Lethargy
- Urinary symptoms
- Gynaecological symptoms - commonly dyspareunia
What are the differentials for acute abdominal pain?
Peritonitis
Ruptured AAA
Hepatic/pancreatic/biliary: Cholecystitis Common bile duct stones Cholangitis Acute pancreatitis
GI: Bowel obstruction Acute mesenteric ischemia Gastro/duodenal ulcer Diverticulitis Gastroenteritis Constipation IBD - chrons disease or ulcerative colitis Strangulated hernia Adhesions Appendicitis
Renal:
Pyelonephritis
Renal colic
Hepatic:
Hepatic abscess
Hepatitis
Reproductive: Ectopic pregnancy Testicular torsion Ovarian cyst rupture or torsion or haemorrhage Pelvic inflammatory disease Pregnancy
Cardiac:
MI
Haematological: Sickle cell crisis DKA Addisonian crisis Hypercalcemia
Which two patient groups are most at risk of mesenteric ischemia?
The elderly - CAD means thrombosis is likely
Those in AF - blood stasis means embolism is likely
What is mesenteric ischemia?
The blockage or occlusion of bowel arteries, often the superior mesenteric artery, nearly always the small intestines are the location.
What are the causes of mesenteric ischemia?
Superior mesenteric artery thrombosis (35% of cases)
Superior mesenteric artery embolism (35% of cases)
Non-occlusive disease (poor cardiac output)
Mesenteric vein thrombosis
Trauma
Vasculitis
Radiotherapy
Strangulation - herniated bowel or volvulus (twisted bowel)
What are the cardinal symptoms of acute mesenteric ischemia?
Often asymptomatic - they look well, pain is the only real symptom
Acute, severe abdominal pain
Pain is in the centre of the abdomen or right iliac fossa
Constant pain
Rapid hypovolaemia and shock
What are the cardinal symptoms of chronic mesenteric ischemia?
Severe colicky abdominal pain (-peristalsis against ischemic area)
Post-prandial pain (-pain upon increasing)
Weight loss (-due to chronic pain on eating)
Potentially plus: N and V Abdominal bruit PR bleeding Malabsorption
What is the major cause of chronic mesenteric ischemia?
Coronary artery disease (CAD)
By which pathophysiological mechanisms does H. Pylori cause increased acid production?
It tends to infect the antrum of the stomach, and therefore causes inflammation to the local cells:
- Inflammation increases gastrin production (more acid production)
- Inflammation suppresses D cell action (less somatostatin, less parietal cell inhibition)
- Inflammation directly induces increased parasympathetic stimulation (increases acid production)
(There is also evidence that the bacteria feeds on mucosal surfactant)
What are the two main causes of gastric ulcers?
NSAIDs
H.Pylori infection
What are the symptoms of a gastric (peptic) ulcer?
Burning/gnawing pain in your upper abdomen, that can radiate to the back or inferiorly
Pain is usually related to eating
Epigastric tenderness
Potentially: Indigestion Heartburn Bloating after fatty foods Nausea and vomiting Early satiety Weight loss Diarrhoea GI bleeds Anaemia symptoms (fatigue,pallor)
What is a gastroduodenal/peptic ulcer?
Lesions in the lining of the gastrointestinal mucosa due to the action of pepsin and stomach acid.
What are the differentials for a burning pain in the epigastrium?
Gastritis Pancreatitis Cholecystitis Hepatitis Peptic ulcer (Perforated) IBS IBD Gastroenteritis Mesenteric ischemia Gastric cancer
By which mechanisms do NSAIDs damage the gastric lining?
- Cytotoxic effect on epithelial cells (direct damage)
- Inhibition of COX-1 enzyme
- decreased mucus production (decreased barrier - most important part!)
- decreased epithelial blood flow (decreased repair)
- suppress prostaglandin production (no effect of prostaglandins to decrease acid production) - Inhibition of COX-2 enzyme
- decreased angiogenesis
- suppress prostaglandin production (no effect of prostaglandins to prevent neutrophil adherence; mucosal damage results)
What does haematemesis look like?
May be bright red (think varices)
May be dark brown, like coffee grounds (think digested blood - bleeding peptic ulcer)
What symptoms might we seen in complications of peptic ulcers?
Fatigue (- iron deficiency anaemia)
Palpitations (- iron deficiency anaemia)
Dyspnoea (- iron deficiency anaemia)
Coffee ground vomit (- haematemesis of digested blood)
Melaena (- black, tarry stools)
Tachycardic (- Haemorrhagic shock)
Collapse/LOC (- Haemorrhagic shock)
Pale (- Haemorrhagic shock)
Agitation (- Haemorrhagic shock)
What are the symptoms of gastric outlet obstruction?
A clinical syndrome characterised by:
Epigastric pain
Postprandial vomiting (-due to mechanical obstruction)
Early satiety
Fullness
Bloating
Weight loss
What are the differentials for gastroparesis? (epigastric pain, postprandial vomiting)
Gastroduodenal ulcers (healing or active)
Gastric cancer
Pancreatitis
Small bowel obstruction
Narcotic bowel syndrome
Functional dyspepsia
Gastric outlet obstruction
IBS
IBD - chrons or ulcerative colitis
What are the causes of gastric outlet obstruction?
Peptic ulcer disease (- antrum scarring causing obstruction)
Pancreatic carcinoma (- extending into the duodenum/gastric outlet)
Gastric carcinoma (- uncommon, present like peptic ulcer disease, picked up mostly on biopsy)
What are the symptoms of gastric cancer?
Persistent indigestion
Trapped wind
Dyspepsia: upper abdominal pain fullness early satiety bloating nausea
Melaena
Loss of appetite
Fatigue
Weight loss
Anaemia: Fatigue, Dyspnoea, Pale
Jaundice
What is gastro-oesophageal reflux disease?
Symptoms or complications that result from the reflux of gastric contents up in to the oesophagus/oral cavity/lung.
Basically: retrograde movement of food
What are the complications of GORD?
Oesophagus:
Ulcer
Haemorrhage
Perforation
Oesophageal stricture
Barrett’s oesophagus
Adenocarcinoma of the oesophagus
What are the signs of gastric cancer?
Epigastric mass
Hepatomegaly
Ascites
Jaundice
Troisiers sign
Acanthrosis nigricans
Which medications are linked with peptic ulcers and GI bleeds?
- 6 main categories -
Antiplatelets
Corticosteroids
NSAIDs
Anticoagulants
Nicorandil (-potassium channel activator: causes refractory bleeds, only stop when nicorandil is stopped)
SSRIs
What are the common differentials for fresh blood in the stool?
Fresh bleeding usually suggests the rectum or anal canal as the source of blood (if the bleed is further up the tract the blood becomes MIXED in with the stool);
Haemorrhoids
Acute anal fissure (-trauma/constipation)
Colorectal tumours (-benign or malignant)
Acute proctitis
IBD (-ulcerative colitis can start as proctitis)
What is an acute anal fissure?
A break/tear in the anal canal (i.e. NOT the rectum). A common condition because the cause is often constipation - a very common condition.
Location: normally extend from the anal opening backwards IN (posteriorly in) to the anal canal, usually midline. The anal wall in the posterior midline is weaker and prone to tears.
Severity - the tear can extend down in to the underlying sphincter muscles
What are the symptoms of an anal fissure?
Severe pain in the anus - often when passing hard stools (ask about constipation);
Bright red anal bleeding - ask if any seen in toilet or on toilet paper
Anal fissure bleeding is never enough to cause anaemia.
What is a GI diverticulum?
An outpouching of the gut wall, generally at areas where perforating arteries (the arteries supplying the colon) enter; weak points.
Location: Colonic - most often the sigmoid colon, but can be in other parts of the GI tract
MOA: High pressure inside the lumen forces the mucosa to herniate through the muscular layer.
Note: 30% of people have diverticula by age 60, but most are ASYMPTOMATIC, they only have “diverticular disease” if the diverticuli are symptomatic
What is diverticulosis?
The presence of diverticula.
What is diverticulitis?
Inflammation of a diverticula.
What is diverticular disease?
A symptomatic diverticula.
What are the symptoms of diverticular disease?
Altered bowel habit
Left sided (LIF or hypogastrium) colic pain relieved by defacation
Nausea
Flatulence
What are the symptoms of diverticulitis?
Same as diverticular disease: Altered bowel habit Left sided colic pain relieved by defacation Nausea Flatulence
Plus the inflammatory symptoms:
Pyrexia
Tender colon
Localised/general peritonism
Signs:
Raised WCC/CRP
What is an acute abdomen?
An acute abdomen is a condition of severe abdominal pain, usually requiring surgery and caused by an acute disease/injury to internal organs.
It is distinct from chronic abdominal pains.
Examples of conditions within “acute abdomen”;
Acute pancreatitis
Duodenal ulcer
Ectopic pregnancy
Which conditions cause acute abdomen of the RUQ?
Note: RUQ doesn’t include the epigastrium, the epigastrium is a small area, bounded by the uppermost part of the costal arch, it also doesn’t include the umbilicus.
Acute cholecystitis Duodenal ulcer Pyelonephritis Right sided Pneumonia referred pain Hepatitis Congestive hepatomegaly
Which conditions cause acute abdomen of the LUQ?
Note: LUQ doesn’t include the epigastrium, the epigastrium is a small area, bounded by the uppermost part of the costal arch, it also doesn’t include the umbilicus.
Ruptured spleen Pneumonia referred pain Gastric ulcer Aortic aneurysm Perforated colon Pyelonephritis Left sided pneumonia - referred pain
Which conditions cause acute abdomen of the RLQ?
Note: RLQ doesn’t include the epigastrium, the epigastrium is a small area, bounded by the uppermost part of the costal arch, it also doesn’t include the umbilicus.
Acute appendicitis Chron’s disease Meckel’s Diverticulitis - small intestine, congenital Constipation Renal colic - renal/ureteric stone Strangulated hernia
Reproductive: Ectopic pregnancy Ruptured ovarian cyst Ovarian abscess Salpingitis
Which conditions cause acute abdomen of the LLQ?
Note: LLQ doesn’t include the epigastrium, the epigastrium is a small area, bounded by the uppermost part of the costal arch, it also doesn’t include the umbilicus.
Sigmoid Diverticulitis Constipation Strangulated hernia Chron’s disease Ulcerative colitis Renal colic - renal/ureteric stones
Reproductive: Ectopic pregnancy Ruptured ovarian cyst Ovarian abscess Salpingitis
Which conditions cause acute abdomen of the Epigastrium?
Peptic ulcer Acute pancreatitis MI Acute cholecytitis Perforated oesophagus
Which conditions cause acute abdomen of the Umbilicus?
Early appendicitis - pain begins centrally and travels to the RIF
Small bowel intestinal obstruction
Acute pancreatitis
Mesenteric thrombosis (mesenteric ischemia)
Diverticulitis
Aortic aneurysm
Which conditions cause acute abdomen of the Suprapubic quadrant?
Acute urinary retention
UTI
Ectopic pregnancy
Which conditions cause acute abdomen across the entire abdomen?
Perforated viscous
Acute pancreatitis
Diabetic ketoacidosis (- gastric distension, hypovolaemia and electrolyte disturbance)
What are the signs of acute abdomen?
Fever (- low grade) Tenderness Rigidity Guarding Rebound tenderness Abdominal distension (- fluid;ascites or gas due to obstruction or foetus in women)
Bowel sound change:
Absent - peritonitis
Increase sounds/high pitched tinkling - small bowel obstruction
Why does normal constipation occur in the descending/sigmoid colon more often?
The ascending colon is processing liquid stool direct from the ileum, the stool has not had the opportunity to be dehydrated and compressed yet.
This means constipation normally occurs in the distal colon (left sided).
Where would constipation potentially occur in the bowels in a patient with ulcerative colitis?
Ascending colon - this is because the descending/sigmoid colon are ulcerated and inflamed, the oedema has prevented stool passing in to this area, and subsequently the stool has collected in the ascending/transverse colon - an unusual area for collection.
Expect the stool to be liquid.
What are the types of hernia?
Inguinal
Femoral (- enters femoral canal)
Obturator (- enters obturator canal)
Umbilical (paraumbilical)
Hiatus
Incisional
Epigastric
Sciatic (- through lesser sciatic foramen)
Lumbar (-through lumbar triangles on posterior abdominal wall)
Spigelian (-below umbilicus at lateral edge of rectum sheath)
Diaphragmatic
Muscular (-muscle herniates from abdomen)
Richter’s
Littre’s
Maydl’s
What is a Richter’s hernia?
Richter’s (- bowel wall herniates, but not the whole piece of bowel, the lumen remains in the abdomen)
What is a littre’s hernia?
Littre’s (- a strangulated meckel’s diverticulum that herniated)
What is a maydl’s hernia?
Maydl’s (- a herniated double loop of bowel, often with the strangulated loop still within the bowel)
What are the most common causes of acute abdomen?
Most common to less common:
Intestinal obstruction
Peritonitis secondary to infection (e.g. appendicitis)
Haemorrhage (e.g. due to ectopic pregnancy or ruptured AAA)
Ischemia (e.g. mesenteric ischemia, ovarian torsion)
Contamination of abdominal compartment with GIT contents (e.g. perforated duodenal/gastric ulcer)
Another way to think of the possible causes: Obstruction Inflammation Perforation Gynaecology Vascular Infection Metabolic Toxic Urology
What are obstructions that cause acute abdomen?
Obstructions: Adhesions - incarceration of a hernia Volvulus Gallstones Intussusception - telescoping of the bowel (bowel invaginates into the adjoining bowel) GI neoplasm Congenital abnormalities IBD
What are the inflammatory causes of acute abdomen?
Inflammation: Cholecystitis Appendicitis Acute pancreatitis Acute diverticulitis Meckel diverticulitis (small intestine diverticulum) IBD
What are the perforations that can cause acute abdomen?
Perforation:
Duodenal/gastric ulcer
Oesophageal perforation
Mallory-Weiss tear (tear of the mucosa at the gastro-oesophageal junction)
What are the gynaecological causes of acute abdomen?
Gynaecological: Ectopic pregnancy Ruptured ovarian cyst Ovarian lesion Pelvic inflammatory disease Endometriosis
What are the vascular causes of acute abdomen?
Vascular: Abdominal aortic dissection Ruptured AAA Ruptured splenic artery aneurysm Mesenteric ischemia/infarction Ischemic colitis Splenic infarct Sickle cell crises Bud-chiari syndrome (occlusion of hepatic veins) Abdominal wall haematoma (due to trauma/exercise/coughing)
What are the infections that cause acute abdomen?
Infection:
Gastroenteritis
Infectious colitis
Typhilitis
Of any para-GI organ (e.g. hepatic abscess)
Pisa’s abscess (often due to TB from the lumbar vertebrae)
What are the metabolic causes of acute abdomen?
Metabolic: Uraemia (renal failure; increased toxins in serum) Diabetic ketoacidosis Addisonian crisis Hypercalcaemia Acute intermittent porphyria
What are the urological causes of acute abdomen?
Urological:
Testicular torsion
Kidney stones
Pyelonephritis
What is acute appendicitis?
Lumen obstruction of the appendix by , means trapped gut bacteria invade the appendix wall, causing oedema, ischaemic necrosis and perforation.
MOA of obstruction:
Lymphoid hyperplasia
Faecolith (faecal concretion/pellet)
Filariasis worms
What are the symptoms of appendicitis?
Abdominal pain:
Early - dull pain in paraumbilical region (navel)
Late - becomes sharp as it moves to RIF
Anorexia - loss of appetite
Associated with pain:
Tachycardia
Fever
Peritonism - guarding, and rebound/percussion tenderness in RIF
Associated with anorexia:
Nausea and vomiting
Often apyrexial
What is Rosvig’s sign in appendicitis?
Rosvig’s sign = pain is felt in RIF when LIF is pressed
What is the psoas sign in appendicitis?
Psoas sign = pain on extending the right hip if the appendix is retrocaecal
What are the signs and symptoms of intussusception?
Redcurrant jelly stool
Recital bleeding
May have vomiting
Colicky Abdominal pain
Signs:
May have abdominal mass usually in RUQ or epigastrium
What is intussusception?
A telescoping of intestine in to another portion of intestine, this drags mesentary with it, obstructing the mesentary. Oedema, mucosal bleeding and pressure occur.
This causes bleeding in to the bowel and can create the redcurrant jelly stools.
Which syndrome affecting the intestines is characterised by vitamin B12 deficiency?
Imerslund-grasbeck syndrome
A rare, autosomal recessive condition affecting the cubilin receptors in the ileum.
So no vitamin B12 can be absorbed
Who is most at risk of C. Diff infections?
Those who are in hospital and have been on antibiotics - “clears the way” for c.dif
What is travellers diarrhoea?
Gastroenteritis (diarrhoea; production of 2+ unformed stools per day) following travel abroad
What is acute gastroenteritis?
3 or more episodes of diarrhoea per day for less than two weeks
What is persistent gastroenteritis?
More than three episodes per day for greater than two weeks
What is a c. Diff infection?
An infection of the colon with the gram positive anaerobes clostridium difficile
C.diff is normally present in the gut, but becomes dominant when other flora is killed off by antibiotics
Produces A and B spore forming rods, forms toxins that causes inflammatory response, and can cause pseudomembrane formation (raised yellow-white plaques in the colon on top of erythematous mucosa), which can lead to toxic megacolon, ileus or colonic perforation and peritonitis
Transmission is most commonly faecal-oral
Incubation time = 2-3 days
Severity grades:
1. Mild - no WCC incr, less than 3 eps of loose stools
2. Moderate - WCC incr and 3-5 loose stools
3. Severe;
WCC over 15 (10^9/L)
Or serum creatinine 50% above baseline
Or temp >38.5
Or radiological signs of severe colitis
4. Life threatening;
Signs of toxic megacolon
Signs of partial or complete ileus (slowing of gastric motility accompanied by distension, without mechanical obstruction - diagnosis of exclusion after obstruction is rules out)
What is toxic megacolon?
Toxic colitis with dilated colon
Signs include abdo pain, distension, hypotension, increased heart rate, fever and chills
What is campylobacter?
Most common cause of gastroenteritis in the uk
Comes from poultry, cattle and domestic animals
Incubation:1-7 days
Transmission - faecal oral
Can cause toxic megacolon
If severe - give macrolides
What is ETEC?
Enterotoxigenic e coli
Causes a very watery diarrhoea (like cholera), with cramps and nausea
Incubation = 12-72 hours
Transmission: oral
What is EHEC?
Enterohaemorrhagic E. coli - E. coli H7O157
From beef and other foods
Does NOT cause fever
Incubation: 12-60 hours
What is salmonella enteriditus and typhimurium?
A pair of types of salmonella
From raw eggs, lizards and other foods
Can cause dysentery
Causes pyrexia
What is enteric fever?
Type of gastroenteritis caused by Salmonella typhi and paratyphi types
From water and food, Carried by humans.
Does not cause dysentery
Can cause meningioencephalitis or osteomyelitis
What is shigella?
A bacterial type of dysentery
Transmission - faecal oral, from human carriers
Incubation - 1-8 days
Can cause toxic megacolon
What is amoebiasis?
Type of gastroenteritis parasitic infection causing cysts throughout the body (abscesses in the liver etc)
Causes dysentery
What is schistomiasis?
A type of parasitic gastroenteritis organism. Lots of different types.
There is a reaction from the immune system causing granuloma formation due to the schistosome eggs, causing severe active colitis.
Need to kill adult worms AND the eggs
