Lower GI Flashcards
Most common cause(s) of small bowel obstruction?
Scar tissue (adhesions) Strangulated Hernias Malignancy Volvulus Crohn's disease
Most common cause of large bowel obstruction?
Cancer Diverticulitis Volvulus Inflammatory bowel disease Constipation
What are this symptoms of bowel obstruction?
Cramping that comes and goes- central umbilical.
Vomiting
Bloating
Constipation and no flatus (complete blockage)
Diarrhoea (partial blockage)
Investigations for ?bowel obstruction?
Abdominal X-ray Erect CXR (air - perf) If inconclusive - early CT Colonoscopy - risk of perf Gastrogaffin enema
Most common cause of ileus?
Abdominal surgery
How to treat ileus?
Drip (fluids and electrolytes)
Suck (NG)
Should recover in 1-3days
What are the symptoms of intussusception in children?
Abdo pain
Lethargy
Bloody/mucus stools (redcurrent jelly)
Vomiting (can be bile stained)
Treatment for intussusception?
Children - enemas/ surgery
Adults - surgery
How to tell the difference between small and large bowel obstruction?
Valvulae coniventes
Small - completely cross lumen
Large - haustra do not cross full lumen
What are the indications for surgery in small bowel obstruction?
Absolute indications: Generalised peritonitis Localised peritonitis Visceral perforation Irreducible hernia
Relative:
Palpable mass
‘Virgin’ abdomen
Failure to improve
When to go for conservative management in small bowel obstruction?
Imcomplete obstruction
Previous surgery
Advanced malignant disease
Diagnostic doubt
Difference in presentation between right and left large bowel tumours causing obstruction?
Right (caecal) - presents like SBO - early vomiting, late constipation.
Left - LBO - change in bowel habit, absolute constipation, abdo distension, late vomiting,
Management of LBO?
Surgery -
Requires fluid and abx prior to surgery. Consent for potential STOMA.
Laparotomy (palpate liver for mets and inspect colon)
Will usually be and hemicolectomy +/- stoma
Other option is colonic stenting
What are the signs of volvulus?
LBO - pain constipation and vomiting
Disproportionate abdo distension
Severe pain and tenderness suggests ischemia
X-ray - bean shaped loop.
What’s the treatment for volvulus?
Sigmoidoscopy- for diagnostic and therapeutics.
Flatus tube can be left in for 2-3 days
80% settle with conservative mx.
Options for surgery if decompression fails or peritonitis.
Treatment for caecal volvulus ?
Surgery usually required - if ischemia needs hemicoloctomy.
If viable consider: reduction (high recurrence), right hemicolectomy, caecostomy, caecopexy.
What Are the indications for Surgery for bowel obstruction?
Strangulation
Closed loop obstruction (eg volvulus)
Which is the most common volvulus?
Sigmoid
What causes a mid gut volvulus?
Usually babies
Malrotation means caecum is at the RUQ not RLQ… allows midgut to move more… and twist to form a volvulus
What is familial adenomatous polyposis syndrome?
Genetic mutation in ACP gene
100/1000s of polyps
Often colon needs to be removed
Causes of small bowel infraction?
Transmural - thrombosis or clots in SMA
Tumour, hernia, volvulus, intussusception etc cause compression of blood vessels
Non-occulasive eg hypoperfusion cause mucosal infarcts. Causes: Hypovolemia and low CO.
Symptoms of small bowel ischemia,
Severe abdominal pain might soft..
When infarct occurs - vomiting and bloody diahorrha and abdo distension might occur
Sepsis - fever, peritonitis
What tests do you do for small Bowel ischemia?
Abdo CT - shows bowel dilation, bowel wall thinkening and intestinal pneumatosis
Can do CT angio - shows the right area
Rx: revascularisation
What’s the surgery for cancer >8 cm above the anal verge?
Anterior resection +/- defunctioning stoma (need a contrast enema prior to reversal of stoma)
What are the causes of anal fissures?
Constipation (causing trauma) - spasm of sphincter causes pain and poor healing (ischemia)
Rarer: chrons , STI (herpes, syphillis, HIV), anal cancer
Presentation (Symptoms and examination)of anal fissures?
Pain passing stool, right red PR bleed (mainly on paper)
PR (often impossible), Ulcer, skin tag. Groin LN suggest complicating factor
Management of anal fissures acute and chronic?
Acute - diet and water advice, 1st line - bulk forming laxative (fybogel), lubricants, topical anesthetiser (lignocaine),
Chronic >6wk -above Mx plus
1st line - topical GTN (try for 8 weeks)
2nd line - referral for surgery or botulinum toxin injection.
Surgery - lateral partial sphincterotomy
What’s the presentation of an anal fistula?
Persistent anal discharge
Perianal Pain and discomfort
Associated with: perianal sepsis (abscess), Crohn’s disease, diverticular disease, rectal Ca, immunosuppression.
Treatment for anal fistula low vs high?
Low vs high depends on whether the fistula crosses the spinchter muscles above the dentate line
Low - fistulotomy and excision (laid open to heal by 2nd intention)
High - suture - a senton - passed through the fistula and gradually tightened over months (stimulates fibrosis of tract, scar tissue holds sphincter together)
When is a hartmanns procedure indicated?
When there is perforation of the rectosigmoid bowel - cause by:
1) colon cancer (often causes LBO)
2) diverticulitis
3) trauma
What is Hartmanns procedure?
Sigmoid colon resection plus end colostomy and rectal stump is sewn.
What’s dukes criteria for colorectal cancer?
1 - confined to bowel wall (95%)
2 - through bowel wall but no LN(80%)
3 - LN involved (65%)
4 - distant mets (5%)
% - 5 year survival
What type of cancer are the majority of colorectal cancers?
Adenocarcinomas
What Are the associations with sigmoid volvulus?
Older patients Chronic constipation Chagas' disease Neurological (PD, DMD) Psych (schizophrenia)
Management for sigmoid volvulus? Vs caelcal volvulus?
Rigid sigmoidoscopy with rectal tube insertion
Caecal - right hemicoloctomy is often needed
Emergency Surgical Treatment for poorly controlled UC (including megacolon)?
Subtotal colectomy
Surgical cure for UC
Protocolectomy
Treatment for UC when medical management isn’t successful wishing to avoid stoma?
Panproctocolectmy with ileoanal pouch.
Which disease presents with nocturnal diarrhoea and incontinence
Inflammatory bowel disease
Specifically proctitis
What are the complications of diverticular disease?
Diverticulitis Haemorrhage Fistula Perf (and peritonitis) Abscess Diverticular phlegom
What is angiodysplasia?
Vascular AV malformation of the gut, where there is unexplained PR bleeding and anemia.
It can be seen on colonoscopy/ endoscopy/ pill entroscopy and is usually in the caecum or ascending colon (right)
Caecal malignancy and scanty polyps, with a death from colorectal cancer in the family at 34, suggests which genetic syndrome?
Lynch syndrome (HNPCC) - need colonoscopy every 1-2 years from 25years old.
Right sided mucinous tumours
Diagnostic investigation for diverticulitis?
CT abdo
