GASTRO Flashcards
Achalasia - Definition
Oesophageal motility disorder:
1) Loss of peristalsis
2) Failure of relaxation of the lower oesophageal sphincter (LOS).
Achalasia - Aetiology & Epidemiology
1) Ganglion cells of the myenteric plexus in the oesophagus degenerate - unknown cause.
2) More common in people with Oesophageal infection with Trypanosoma cruzi seen in Central/S. America produces a similar disorder (Chagas disease).
Epidemiology: Annual incidence is about 1 in 100,000. Usual presentation age: 25–60 years.
Achalasia - History
- Presenting symptoms of achalasia…
- Recognise the signs of achalasia on physical…
Insidious onset, gradual progression of:
1) intermittent dysphagia (difficulty swallowing) involving solids and liquids;
2) difficulty belching (burping);
3) regurgitation (particularly at night);
4) heartburn
5) chest pain (atypical/cramping, retrosternal);
6) weight loss.
Achalasia - Investigations
1) CXR - may show widened mediastinum and double right heart border (dilated oesophagus), an air-fluid level in the upper chest and absence of the normal gastric air bubble.
2) Barium swallow: Dilated oesophagus which smoothly tapers down to the sphincter (beak- shaped).
3) Endoscopy: To exclude malignancy which can mimic achalasia.
4) Manometry: A test used to measure the function of the lower esophageal sphincter (the valve that prevents reflux of gastric acid into the esophagus) and the muscles of the esophagus…
- Elevated resting LOS pressure (>45 mmHg);
- incomplete LOS relaxation;
- absence of peristalsis in the distal (smooth muscle portion) of the oesophagus.
5) Serology for antibodies against T. cruzi if Chagas disease is suggested by epidemiology and
symptoms. Blood film might detect parasites.
Achalasia - Management
& Complications & Prognosis
1) Pneumatic balloon dilation of the LOS: Up to 80% short-term success rate, 2–6% risk of oesophageal perforation.
2) Heller myotomy - surgery where LOS muscles cut, allowing food to pass to the stomach. Surgery can be complicated by reflux oesophagitis and some surgeons combine it with a fundoplication procedure to prevent reflux. Recently, laparoscopic/ thoracoscopic techniques to perform myotomy.
3) Botulinum toxin injected into the LOS inhibits acetylcholine release from the excitatory neurons that increase smooth muscle tone. The long-term safety/efficacy remain uncertain.
4) Medical treatment: Nitrates and calcium channel blockers (e.g. nifedipine) may be used to relax the smooth muscle of the LOS. Medical treatment is often ineffective, and may be associated with side effects (e.g. headache, hypotension) and tachyphylaxis.
COMPLICATIONS: If untreated, aspiration pneumonia (infection after inhaling vomit) , malnutrition and weight loss. 15 x risk of oesophageal malignancy, (on average 15 years after diagnosis).
PROGNOSIS: Good if treated. If untreated, oesophageal dilation may worsen causing pressure on mediastinal structures.
Coeliac disease - Definition
Inflammatory disease caused by intolerance to gluten, causing chronic intestinal malabsorption.
Coeliac disease - Aetiology & Epidemiology
Sensitivity to the gliadin component of gluten, triggers an immunological reaction in the small intestine leading to mucosal damage and loss of villi. 10% risk of first-degree relatives being affected, clear genetic susceptibility associated with HLA-B8, DR3 and DQW2 haplotypes.
EPIDEMIOLOGY: UK prevalence is 1 in 2000. One in 300 in the west of Ireland; rare in East Asia.
Coeliac disease - History
May be asymptomatic.
Abdominal discomfort, pain and distention.
Steatorrhoea (pale bulky stool, with offensive smell and difficult to flush away), diarrhoea.
Tiredness, malaise, weight loss (despite normal diet).
Failure to thrive in children, amenorrhoea (absence of menstruation) in young adults.
Coeliac disease - Examination
1) Signs of anaemia: Pallor.
2) Signs of malnutrition: Short stature, abdominal distension and wasted buttocks in children.
3) Triceps skinfold thickness gives an indication of fat stores.
4) Signs of vitamin or mineral deficiencies (e.g. osteomalacia, easy bruising).
5) Intense, itchy blisters on elbows, knees or buttocks (dermatitis herpetiformis).
Coeliac disease - Investigations
1) Blood: FBC (low Hb), iron and folate, U&E, albumin, Ca2+ and phosphate.
2) Serology (blood serum): Testing for IgG anti-gliadin (AGA), IgA and IgG anti-endomysial transglutaminase antibodies can be diagnostic. As IgA deficiency is common (1 in 50 with coeliac disease) immunoglobulin levels should also be measured to avoid false negatives.
3) Stool: Culture to exclude infection, faecal fat tests for steatorrhoea.
4) D-xylose test: Reduced urinary excretion after an oral xylose load indicates small bowel malabsorption.
5) Endoscopy: Shows villous atrophy in the small intestine (particularly jejunum and ileum) mucosa looks flat and smooth. Biopsy shows villous atrophy with crypt hyperplasia of the duodenum. The epithelium adopts a cuboidal appearance, and there is an inflammatory infiltrate of lymphocytes and plasma cells in the lamina propria.
Coeliac disease - Management
Advice: Stop eating gluten, avoid all wheats, rye and barley. Expert dietary advice is essential.
Medical: Vitamin and mineral supplements. Oral corticosteroids if disease does not subside with gluten withdrawal.
C O M P L I C A T I O N S: Iron, folate and Vitamin B12 deficiency, osteomalacia (soft bones, Vit D/calcium def) , ulcerative jejunoileitis, gastrointestinal lymphoma (particularly T cell), bacterial overgrowth. Rarely, can cause cerebellar ataxia.
P R O G N O S I S: With strict adherence to gluten-free diet, most patients make a full recovery. Symptoms usually resolve within weeks. Histological changes may take longer to resolve. A gluten-free diet for life.
X - NOT ON SOFIA. Colonic polyps - Definition
A protuberance into the lumen from the normally flat colonic mucosa.
X- NOT ON SOFIA. Colonic polyps - Aetiology
Classified into neoplastic and non-neoplastic:
Neoplastic polyps include adenomas ( two-thirds of all colonic polyps) and adenocar-
cinomas.
Non-neoplastic polyps include hyperplastic polyps, inflammatory pseudopolyps (islands of
residual intact colonic mucosa resulting from mucosal ulceration and regeneration that occurs in inflammatory bowel disease), and hamartomatous polyps, e.g. in Peutz-Jeghers syndrome (autosomal dominant disorder associated with mucocutaneous pigmentation of lips and gums) and Cronkhite-Canada syndrome (associated with alopecia, nail atrophy, cutaneous hyperpigmentation and watery diarrhoea).
Multiple colonic polyps occur in familial adenomatous polyposis (FAP) and its variants such as Turcots syndrome (FAP associated with glioblastomas or medulloblastomas) and Gardners syndrome (FAP associated with osteomas, soft-tissue tumours, sebaceous cysts). These are autosomal dominant diseases caused by mutations in the adenomatous polyposis coli (APC) gene.
X - NOT ON SOFIA. Colonic polyps - History & Exam
Usually asymptomatic.
May cause a change in bowel habit, tenesmus if in the rectum. Mucoid diarrhoea.
PR bleeding (in case of polyp ulceration).
Symptoms of anaemia.
EXAM: Usually no findings on examination. May be palpable on PR examination if low in rectum. Associated features of the syndromes mentioned above.
X - NOT ON SOFIA
Colonic polyps - Investigations
& Management
Blood: FBC (look for microcytic anaemia).
Stool: Occult or frank blood in stool.
Endoscopy: Colonoscopy is the gold standard investigation. For multiple polyposis syn-
dromes, an upper GI endoscopy is necessary to look for upper GI polyps. Polyps removed need to be histologically examined to determine their malignant potential.
MANAGEMENT:
Colonoscopic polypectomy for small isolated polyps. Large polyps may have to be surgically resected. In multiple polyposis syndromes (particularly FAP), early colectomy is recommended to reduce risk of malignancy.
Follow-up: The timing of the next follow-up colonoscopy depends on the number, size and histology of polyps, family history, preferences of the patient and judgment of the physician. Guidelines suggest:
for 1–2 small (< 1 cm) tubular adenomas with low-grade dysplasia: 5 years;
for 3–10 adenomas, or any adenoma 1cm, with villous features, or high-grade dysplasia: 3 years;
for >10 adenomas: < 3 years;
for a large (>2 cm) sessile polyp: 2–6 months to ensure complete removal.
Genetic screening of relatives may be necessary in multiple polyposis syndromes.
Colorectal carcinoma - definition
Malignant adenocarcinoma of the large bowel.
Colorectal carcinoma - Aetiology
Environmental & genetic factors.
Epithelial dysplasia leading to adenoma (benign from glandular epith) and then carcinoma is thought to occur, involving accumulation of genetic changes in oncogenes (e.g. APC, K-ras) and tumour suppressor genes (e.g. p53, DCC).
- 60% in rectum & sigmoid colon
- 20% in the ascending colon
- Rest in transverse & descending
Chronic bowel inflammation (e.g. IBD) also increases the risk of
colorectal carcinoma.
Colorectal carcinoma - History
Symptoms depend on location of the tumour.
1) Left-sided colon and rectum: Change in bowel habit, rectal bleeding or blood/mucous mixed in with stools. Rectal masses may also present as tenesmus (sensation of incomplete
emptying after defecation).
2) Right-sided colon: Later presentation, with symptoms of anaemia, weight loss and non-specific malaise or, more rarely, lower abdominal pain.
3) Up to 20% of tumours will present as an emergency with pain and distension caused by large bowel obstruction, haemorrhage or peritonitis as a result of perforation.
Colorectal carcinoma - Examination
- Anaemia may be only sign, particularly in right-sided lesions.
- Abdominal mass, low-lying rectal tumours may be palpable on rectal examination.
- Metastatic disease: Hepatomegaly, shifting dullness of ascites.
Colorectal carcinoma - Investigations
1) Blood: FBC (for anaemia), LFT, tumour markers (CEA to monitor treatment response or disease recurrence).
2) Stool: Occult or frank blood in stool (can be used as a screening test).
3) Endoscopy: Sigmoidoscopy, colonoscopy. Allows visualization and biopsy. Polypectomy can also be performed if isolated small carcinoma in situ.
4) Barium contrast studies: Apple core stricture on barium enema. 5) Abdominal ultrasound scan for hepatic metastases.
6) Other staging investigations include CXR, CT or MRI, endorectal ultrasound.
Colorectal carcinoma - Management & Complications & Prognosis
Surgery: Surgery only curative treatment.
- Caecum, ascending, proximal transverse colon: Right hemicolectomy.
- Distal transverse colon, descending: Left hemicolectomy.
- Sigmoid colon: Sigmoid colectomy.
- High rectum: Anterior resection.
- Low rectum: Abdo-perineal resection and end colostomy formation.
- Emergency: Hartmanns procedure (proximal colostomy, resection of tumour and oversew of distal stump).
Survival improved if total mesorectal excision (removal of surrounding fascia). Isolated hepatic metastases may be successfully resected.
Radiotherapy: May be given in a neoadjuvent setting to downstage rectal tumours prior to resection or as adjuvant therapy to reduce risk of recurrence.
Chemotherapy: Used as adjuvant therapy in Dukes C, or sometimes B. 5-Fluorouracil, oxaliplatin and irinotecan are common drugs in first-line chemotherapy protocols; newer agents like cetuximab (monoclonal against EGFR-receptor) and bevacizumab (monoclonal against VEGF) may be considered in metastatic disease or in the context of clinical trials.
COMPLICATIONS: Bowel obstruction or perforation, fistula formation. Recurrence. Metastatic disease.
PROGNOSIS: based on Dukes staging.
Crohn’s Disease - Definition
Chronic granulomatous inflammatory disease that can affect any part of the gastrointestinal tract. Grouped with ulcerative colitis and together they are known as inflammatory bowel disease.
Crohn’s Disease - Aetiology & Epidemiology
Unknown cause, genetic & environmental factors.
Inflammation occurs anywhere along GI tract (40% involving the terminal ileum) and skip lesions with inflamed segments of bowel interspersed with normal segments is not unusual. CROHNS IS CRAY - hence it doesnt seem to have a pattern.
EPIDEMIOLOGY: Annual UK incidence is 5–8 in 100,000. Prevalence is 50–80 in 100,000. Affects any age but peak incidence is in the teens or twenties.
Crohn’s Disease - History
1) Crampy abdominal pain (caused by inflammation, fibrosis or bowel obstruction).
2) Diarrhoea (may be bloody or steatorrhoea).
3) Fever, malaise, weight loss.
4) Symptoms of complications.
Crohn’s Disease - Examination
1) Weight loss, clubbing, signs of anaemia.
2) Aphthous ulceration of the mouth (igloo for life).
3) Perianal skin tags, fistulae and abscesses.
4) Signs of complications (eye disease, joint disease, skin disease).
Crohn’s Disease - Investigations
1) Blood: FBC (low Hb, high platelets, high WCC), U&E, LFTs ( low albumin), high ESR, CRP (high or may be normal), haematinics to look for deficiency states: ferritin, Vitamin B12 and red cell folate.
2) Stool microscopy and culture: To exclude infective colitis.
3) AXR: For evidence toxic megacolon.
4) Erect CXR: If risk of perforation.
5) Small bowel barium follow-through: May reveal fibrosis/strictures (string sign of Kantor), deep ulceration (rose thorn), cobblestone mucosa.
6) Endoscopy (OGD, colonoscopy) and biopsy:
- May help differentiate between UC & Crohns; monitors malignancy and disease progression.
- Mucosal oedema and ulceration with rose-thorn fissures (cobblestone mucosa), fistulae, abscesses.
- Transmural chronic inflammation with infiltration of macrophages, lympho- cytes and plasma cells.
- Granulomas with epithelioid giant cells may be seen in blood vessels or lymphatics.
7) Radionuclide-labelled neutrophil scan: Localization of inflammation (when other tests are contraindicated).
Crohn’s Disease - Management
1) Acute exacerbation: Fluid resuscitation, IV or oral corticosteroids, 5-ASA analogues (e.g. mesalazine, sulfasalazine) may induce a remission. Analgesia. Elemental diet may induce remission (more often used in children). Parenteral nutrition may be necessary. Monitor markers of activity (fluid balance, ESR, CRP, platelets, stool frequency, Hb and albumin). Assess for complications.
2) Long term:
- Steroids: For treating acute exacerbations.
- 5-ASA analogues (e.g. sulfasalazine, mesalazine): # relapses. Useful for mild-to-moderate
disease.
- Immunosuppression: Using steroid-sparing agents (e.g. azathioprine, 6-mercaptopurine,
methotrexate) to # relapses.
- Anti-TNF agents (e.g. infliximab, adalimumab): Very effective agents in achieving and maintaining remission. Usually reserved for refractory cases.
3) Advice: Stop smoking, dietician advice.
4) Surgery: If above fails, failure to thrive in children or if complications. Affected bowel resected, stoma made. Risk of recurrence.
Crohn’s Disease - Complications & Prognosis
GI: Haemorrhage, bowel strictures, perforation, fistulae (between bowel, bladder, vagina), perianal fistulae and abscess, GI carcinoma (5% risk in 10 years), malabsorption.
Extraintestinal features: Uveitis, episcleritis, gallstones, kidney stones, arthropathy, sa- croiliitis, ankylosing spondylitis, erythema nodosum and pyoderma gangrenosum, amyloidosis.
PROGNOSIS: Chronic relapsing condition. Two-thirds will require surgery at some stage and two-thirds of these >1 surgical procedure.
Diverticular disease - Definition
- Diverticulae: outpouchings of colonic mucosa/submucosa throught muscular wall of large bowel.
- Diverticulosis: presence of diverticulae
- Diverticular disease: Diverticulosis associated with complications, e.g. haemorrhage, infection, fistulae.
- Diverticulitis: Acute inflammation and infection of colonic diverticulae.
Hinchey classification of acute diverticulitis: Ia: phlegmon, Ib and II: localized abscesses,
III: perforation with purulent peritonitis or IV: faecal peritonitis.
Diverticular disease - Aetiology & Epidemiology
Low-fibre diet= constipation. Thus, high colonic intraluminal pressures, herniation of mucosa and submucosa through the muscularis, particularly at sites of nutrient artery penetration.
Pathogenesis: Diverticulae most common in sigmoid and descending colon, but can be right sided. Absent from the rectum. Diverticulae get blocked by poop = bacterial overgrowth, toxin production and mucosal injury and diverticulitis, perforation, pericolic phlegmon, abscess, ulceration and fistulation or stricture formation.
EPIDEMIOLOGY: Common, 60% of people living in industrialized countries will develop colonic diverticula, rare < 40years. Right-sided diverticula are more common in Asia.
Diverticular disease - History
Often asymptomatic (80–90%). Complications include: pr bleeding Diverticulitis: typically, left iliac fossa or lower abdominal pain, fever. Diverticular fistulation into bladder: pneumaturia (gas in urine), faecaluria and recurrent UTI.
Diverticular disease - Examination
Diverticulitis: Tender abdomen; signs of local or generalized peritonitis if perforation has occurred.
Diverticular disease - Investigations
1) Bloods: FBC, high WCC & CRP in diverticulitis, check clotting and cross-match if bleeding.
2)Barium enema ( +/- air contrast): Demonstrates the presence of diverticulae with a saw- tooth appearance of lumen = pseudohypertrophy of circular muscle (not performed in acute setting as danger of perforation).
3) Flexible sigmoidoscopy and colonoscopy: Diverticulae can be seen and other pathology (e.g. polyps or tumour) can be excluded.
In an acute setting: CT scan for evidence of diverticular disease and complications.
Diverticular disease - Management, Complications & Prognosis
1) Asymptomatic: Soluble high-fibre diet (20–30 g/day). Probiotics and anti-inflammatories (mesalazine) are under investigation for preventing recurrent flares of diverticulitis.
2) GI bleed: PR bleeding is often managed conservatively with IV rehydration, antibiotics, blood transfusion if necessary. Angiography and embolization or surgery if severe.
3) Diverticulitis: Treated by IV antibiotics and IV fluid rehydration and bowel rest. Localized collections or abscesses may be treated by radiologically sited drains.
4) Surgery: May be necessary with recurrent attacks or when complications develop, e.g. perforation and peritonitis. Surgical treatment can be by open or laparoscopic approaches. Open: Hartmanns procedure (resection and stoma) or one-stage resection and anastomosis (risk of leak) defunctioning stoma.
More recently, laparoscopic drainage, peritoneal lavage and drain placement can be effective.
COMPLICATIONS: Diverticulitis, pericolic abscess, perforation, faecal peritonitis, colonic obstruction, fistula formation (bladder, small intestine, vagina), haemorrhage.
PROGNOSIS: Ten to 25% of patients will have one or more episodes of diverticulitis. Of these, 30% will have a second episode.
Gall Stones- Definition
Acute Cholecystitis: Stone or sludge impaction in neck of gall bladder = continuous epigastric or RUQ pain. Referred to the right shoulder, vomiting, fever, local peritonism (shock, ab pain, tenderness, vom), or a GB mass. Main difference from biliary colic is the inflammatory compenent ( high WCC, peritonism, fever). If stone moves to the common bile duct, obstructive jaundice and cholangitis may occure.
{Biliary colic doesnt have jaundice or fever/high WCC, it is just pain. While cholangitis has pain, fever and jaundice.}
Chronic Cholecystitis: Chronic inflammation and colic. ‘Flatulent dyspepsia’: vague abdominal discomfort, distension, nausea, flatulence, fat intolerance (fat causes cholecystokinin release and GB contraction)
Gall stones - Aetiology
Mixed stones: Contain cholesterol, calcium bilirubinate, phosphate and protein (80%). Associated with older age, female, obesity, parenteral nutrition, drugs (OCP, octreotide), family history, ethnicity (e.g. Pima Indians), interruption of the enterohepatic recirculation of bile salts (e.g. Crohns disease), terminal ileal resection.
Pure cholesterol stones (10%): Similar associations as mixed stones.
Pigment stones (10%): Black stones made of calcium bilirubinate (“ bilirubin secondary to haemolytic disorders, cirrhosis), brown stones due to bile duct infestation by liver fluke Clonorchis sinensis. Associated with haemolytic disorders (e.g. sickle cell, thalassemia,
hereditary spherocytosis).
Gall stones - History
(90% gallstones asymptomatic: Found incidentally.)
1) Acute Cholecystitis: Patient unwell, fever, prolonged continuous epigastric or RUQ pain, may be referred to right shoulder (due to diaphragmatic irritation). Vomiting, local peritonism (shock, ab pain, tenderness, vom), or a GB mass.
{Main difference from biliary colic is the inflammatory component ( high WCC, peritonism, fever). If stone moves to the common bile duct, obstructive jaundice and cholangitis may occur. {Cholangitis has pain, fever and jaundice.}
2) Ascending cholangitis: Classical association between right upper quadrant pain, jaundice and rigors (shiver even on fever) = (Charcots triad). If combined with hypotension and confusion, it is known as Reynolds pentad.
3) Biliary colic: Sudden onset, severe right upper quadrant or epigastric pain, constant in nature. May radiate to right scapula, often precipitated by a fatty meal. Can last hours,
may be associated nausea and vomiting.
- Biliary colic doesnt have jaundice or fever/high WCC, it is just pain.
