Benign diseases of the large bowel Flashcards
What are the 5 most common diseases of the large bowel?
Carcinoma of the colon and rectum Colonic polyps Crohn's disease and Ulcerative colitis Diverticular disease Functional disorders
What is a colonic volvulus?
Twristing of the colon. Colonic volvulus is a rare cause of large bowel obstruction, but more common than small bowel volvulus. The sigmoid is most frequently involved, with redundant colon as the primary cause. Cecal volvulus most commonly is due to lack of fixation.
What is colonic angiodysplasia?
angiodysplasia is a small vascular malformation of the gut. It is a common cause of otherwise unexplained gastrointestinal bleeding and anemia. Lesions are often multiple, and frequently involve the cecum or ascending colon, although they can occur at other places.
What is a diverticulum?
an abnormal sac or pouch formed at a weak point in the wall of the alimentary tract.
What is the difference between true and false diverticulum?
True diverticula involve all layers of the structure, including muscularis propria and adventitia, such as Meckel’s diverticulum. False diverticula do not involve muscular layers or adventitia. False diverticula, in the GI tract for instance, involve only the submucosa and mucosa.
True diverticulum tend to be congenital, false diverticulum are acquired with age. WHat are the causes?
Western diet that is low in fibre and hard impacted stool due to chronic dehydration
What is the most common area of the bowel to be affected by diverticulosis?
Sigmoid colon as this stores faeces
What is the difference between diverticulosis and diverticulitis?
Diverticulosis is just the presence of diverticulae
Diverticulitis is inflammation of the diverticulae.
How is diverticulosis diagnosed?
SIgmoidoscopy, barium enema
What are the common clinical features of diverticulitis?
Pain in the left iliac fossa, Septic, altered bowel habit.
Diverticulitis in the caecum and ascending colon can mimic which other disease?
Appendicitis
What are the complications of diverticulitis resulting in complicated diverticulitis?
Pericolic abscess/pelvic abscess
Perforation => pain, change in bowel habit, peritonitis
Lower GI haemorrhage if the infection and necrosis erodes into a blood vessel
Fistula
Stricture
WHat is a fistula and what are the common fistulas which can be a complication of diverticulitis?
An abnormal communication between two epithilial surfaces.
Colovesical fistula (colon/bladder)
Colovaginal fistula.
What are the symptoms of a colovesical fistula?
Recurrent UTIs and pneumaturia (passing bubbles in urine)
Water and bacteria from the colon entering the bladder.
When would you suspect a colovaginal fistula?
Previous hysterectomy and recurrent vanginosis
What causes fistulas due to diverticular disease?
Abscess than erodes into another organ
What are the most common causes of strictures in the large intestine?
Diverticular disease
Tumours
Colitis
What classification is used for diverticular disease? Explain each stage
Hinchey Classification for Acute diverticulitis.
Stage 0 = uncomplicated diverticulitis
Stage 1 = Confined pericoli inflammation and abscess <5cm in close proximity
Stage 2 = Intra-abdominal abscess, pelvic or retroperitoneal abscess distant from the primary site
Stage 3 = Generalised purulent peritonitis
Stage 4 = Faecal peritonitis
Roughly how would you treat stage 0-4 diverticulitis?
0 = self limiting, community management, ?oral antibiotics 1 = IV antibiotics 2 = CT guided drainage by interventional radiology + IV antibiotics 3 = Laproscopic lavage and IV antibiotics 4 = Resection and anastamosis
Is bowel rest or IV fluids beneficial for uncomplicated diverticulitis?
No
What are the options for treatment of complicated diverticulitis?
Percutanious drainage- interventional radiology and CT guided Laproscopic lavage and drainage. Hartmann's procedure (cutting out the diseased colon and bringing the proximal healthy part out to a permanent colostomy and stoma (uncommon) Primary resection and anastamosis
What are the causes of colitis?
Infective
IBD (Crohn’s and UC)
Ischemia
What is colitis?
Inflammation of the colon
What are the common organisms causing infective colitis?
E.coli, campylobacter, salmonella. C diff (pseudomembranous colitis)
What are the symptoms of acute and chronic colitis?
Diarrhoea +/- blood
Abdominal cramps
Dehydration
Sepsis
Chronic add Weight loss and anaemia
How do you investigate and diagnose colitis?
Plain X ray Sigmoidoscopy and biopsy +/- CT scan Stool cultures (check if infective) Barium enema (rare)
What are the typical radiological findings of colitis?
Lead piping of descending colon- featureless
Thumb printing on the ascending colon due to severe mucosal inflammation.
What is the treatment for UC or Crohn’s colitis?
IV fluids
IV steroid (only when infective/ischemic colitis ruled out)
GI rest
Give this supportive treatment for 3 days, if no improvement then consider surgery or potent immunosupressives
What are the causes of ischemic colitis?
Anything which interrupts the blood supply to the intestine (atherosclerosis, thrombosis, embolism)
Therefore more common in elderly, diabetics, hypertensives, high cholesterol.
What is the treatment fro acute ischemia of the bowel?
Surgical emergency.
Prevent necrosis and inflammatory cell invasion as this will lead to destruction of the entire bowel.
What is the most common site of ischemic colitis?
Water shed areas- these are the area between the arteries.
Splenic flecture- between the middle colic and left colic artery.
Where is the most common site of crohn’s colitis?
Terminal ileum
What are the signs fo chronic ischemic colitis?
Intermittent pain, especially after a meal. A bit like angina or a TIA
Where is the most common site for colonic angiodysplasia?
Caecuma nd ascending colon. Obscure cause of rectal bleeding as it can heal and then reoccur and if yu investigate when healed you do not find abnormalities
How can Colonic angiodysplasia be diagnosed?
Difficult
Angiography (go to investigation if someone is having a bleed)
Colonoscopy
How is colonic angiodysplasia treated?
Injection causing embolisation trough a catheter through radial or femoral artery.
Endoscopic ablation.
Hardly ever require surgery
What are the causes of bowel bstruction?
Colorectal cancer
Benign stricture (diverticulosis)
Volvulus
What are the most common sites for volvulus of the large bowel?
Sigmoid colon
Caecum
Transverse colon
Small bowel in paediatrics
What are the 4 cardinal symptoms of large bowel obstruction?
Absolute constipation
Abdominal distention
Pain
Vomiting
What is the treatment for large bowel obstruction?
Resuscitate
Operate
Stenting
What happens if the sigmoid volvulus twists more than 360 degrees?
Ischemia and infarction => gangrenous
Which patient groups are most likely to get sigmoid volvulus and how is it diagnosed?
Elderly, bed bound these are not good candidates for surgery.
Diagnosis on history, abdominal X ray and occasionally rectal contrast
What is the treatment for sigmoid volvulus?
Flatus tube/flexible sigmoidoscopy. Decompression.
Surgical resection
What is pseudo-obstruction and which patients get it?
WHere there is no real mechanical obstruction.
Elderly and debilitated patient. Have the classic signs of obstruction but on investigation, no cause is found.
What could you look for in pseudo-obstruction which may be causing constipation?
Electrolyte disturbaces- Hypokalemia
Biochemistry
Chronic constipation is a functional bowel disorder. How is it treated?
Most people its due to chronic dehydration, diet low in fibre, too much caffeine so dietary cahges/laxatives
Few people have slow transit constipation and motility disorders and you must find the cause (low K+ etc)
Faecal impaction is another functional bowel syndrome. Which patients commonly suffer and how is it treated?
Most common in elderly, bed ridden or people on strong analgesics.
Treated with enemas, laxatives or manual evaculation.
In young people check thyroid function and parathyroid (metabolism of Ca++)
