Small intestine and appendix Flashcards
List the symptoms and signs of acute appendicitis
Symptoms:
- Abdominal pain, starting dull and central before becoming localised and sharp in the RIF at McBurneys point (1/3rd of the way between the ASIS and the umbilicus)
- Constipation (or sometimes diarrhoea)
- Anorexia
- Nausea & vomiting (after the pain)
Signs:
- Rebound (when examiner moves hand away) tenderness in RIF
- Percussion tenderness
- Guarding
- Rosving’s sign (more painful in RIF than LIF when LIF pressed)
- Tachycardia
- Mild fever, flushing and fetor
- Tender mass (ocassionally)
- Psoas sign (pain on R hip extension: retropertioneal retrocaecal appendix)
- Obturator sign (pain on internal rotation of R hip: pelvic appendix)
What other conditions that mimic acute appendicitis?
(other differential diagnosis’)
- Mesenteric lymphadenitis (inflammation of lymph nodes)
- Ovarian cyst rupture
- Eptopic pregnancy
- Caecal volvulus
- Psoas abscess
- Diverticulitis
- IBD
- Cancer
- Pyelonephritis
- Meckel’s Diverticulum
What investigations would you do for a patient with suspected acute appendicitis?
- PR (rectal examination)
- Pelvic examination in females
- Pregnancy test
- Bloods: FBC, U&E, CRP/ESR
- Urinalysis
- USS/CT - if diagnostic uncertainity
- AXR/erect CXR - if questioning perforation
This diagnosis is made clinically and there usually isnt the need for all these tests (esp AXR/erect CXR and USS/CT)
What labatory findings would tend to confirm the diagnosis of acute appendicitis?
Raised WBC
Raised CRP
List the complications of a perforated appendix
(5)
- Peritonitis & sepsis (septicaemia)
- Appendix mass - inflamed appendix becomes covered with omentum
- Appendix abscess - Local/pelvic/subhepatic/subphrenic: develop if appendix mass fails to resolve
- Adhesions (fibrous bands that form between tissues and organs)
- Infertility - due to tubal obstruction after pelvic infection
What are common complications following an appendicetomy?
Early complications:
- Haematoma( a solid swelling of clotted blood within the tissues)
- Wound infections
Late complications:
- Small bowel obstruction (adhesions)
- Incisional hernia
How is the cause of a mass in the RIF diagnosed?
I.e what investigations are required?
- USS/CT to confirm diagnosis (use clinical signs to make inital diagnosis)
What are the possible differenial diagnosis’ for a mass in the right iliac fossa?
- Inflammatory mass (appendix ass/abscess)
- Lymphoma
- Crohn’s disease - Repeated inflammation and fibrosis may cause a thickening
- Tumour mass (caecal/carcinoid)
- Pelvic kidney - transplanted in RIF as external iliac vessels are easy to construct anastomosis with the existing renal vasculature stubs
How is a mass in the RIF managed?
(after USS/CT to confirms diagnosis)
- Conservative management
- IV cefuroxime and metronidazole, marking out the size of the mass to see if it develops into an abscess
- If the mass does not resolve (20% enlarge in a toxic patient), perform percutaneous drainage of abscess
- After resolution, interval appendectomy is usually carried out at three months due to the risks of further attacks
What is a carcinid tumour?
Describe in detail
(not one of the objectives)
- Tumours of argentaffin cells, which produce physically active substances such as serotonin/prostaglandins
- They can often occur on the tip of the appendix, and 10% of tumours may be assoiciated with MEN-1 syndrome
- They charactistically take up silver stains very readily
- Usually present after the fourth decade with carcinoid syndrome (flushing of the face and diarrhoea due to the endocrine products)
- Prognosis is generally good, and the tumour is generally resectable
What is the cause of Meckel’s diverticulum?
What is Meckel’s diverticulum - where?
- Caused by a remnant of the embryological vitelloinstestinal duct (2% of population have it)
- Only 2% of people with Meckel’s develop symptoms
- The diverticulum is 2cm long, on the antimesenteric border of the bowel, 20 inches from the ileocecal valve
- It may be lined by gastric acid secreting epithelium, or heterotropic pancreatic tissue

What are the possible patholigical effects of Meckel’s diverticulum?
-
Caecal volvulus
- part of the colon twists on its mesentery, resulting in acute, subacute, or chronic colonic obstruction
- If tethered to the umbilicus, the diverticulum may act as the apex of a volvulus to present like a volvulus with obstruction
-
Intussusception
- Part of the intestine folds into the section next to it
- Often gangrenous by the point of operation
-
Appendicitis
- Diverticulum becomes inflamed, presenting identical to appendicitis (sometimes also with umbilical cellulitis)
-
Peptic ulceration
- Pain around umbilicus that is related to mealtimes, due to ulceration of the gastric acid secreting epithelium
- A sinus tract may also exist between the diverticulum and the umbilicus (patent viteloointestinal duct)
Describe the signs and symptoms in a patient with intestinal obstruction
Symptoms:
- Vomiting
- Undigested food suggests gastric outlet obstruction
- Bilous vomiting suggests upper small bowel obstruction
- Faeculent vomiting (thicker/foul-smelling) suggests more distal small bowel obstruction
- Pain
- Colicky abdominal pain in early obstruction
- Pain may be absent in long-standing obstruction
- Constipation
- May not be absolute (no passage of wind) in proximal obstruction
Signs:
- Distention
- Tinkling bowel sounds
- Dehydration
- Central resonance to percussion, dull flanks
- Scars: previous surgery causing adhesions
- Palpable mass (causing obstruction)
- NO abdominal tenderness (unless strangulation)
List the common causes of small bowel obstruction
- Adhesions (80%) - extramural
- Hernias - extramural
- Crohn’s disease - intramural
- Intussusception (part of the intestine folds into the section next to) - intramural
List the common causes of large bowel obstruction
- Carcinoma of the colon - intramural
- Diverticular disease - intramural
- Sigmoid volvulus - extramural
- Constipation (forgein body or faecal impaction ect) - intraluminal
What are the complications of bowel obstruction?
- The bowel wall becomes oedematous (tissue with excess interstitial fluid) and distends
- Bacteria proliferate in the obstructed bowel
- As the bowel distends, vessels become stretched and the blood supply is compromised, leading to strangulation (→ ischaemia & necrosis)
- Eventually the bowel will perforate
- Symptoms develop more gradually in large bowel obstruction due to the capacity (even greater if the ileo-caecal valve is incompetent)
What investigations should be done for a patient with suspected small intestinal obstruction?
- Bloods: FBC, U&Es, Amylase, LFTs
- ABG
- Urinalysis
- Supine AXR: distened proximal bowel, absent gas distally
- Erect CXR: fluid levels in small bowel obstruction, air under diaphragm if perforation
- Contrast enema: differentitates obstruction and pseudo-obstruction, can identify the level of obstruction and ileo-caecal competency (gastrograffin may also have therapeutic effect)
- CT scan: can indicate level of obstruction, but cannot always give the diagnosis
Interpret these AXRs

Bowel obstruction on AXR; (1) Small bowel obstruction, showing valvulae conniventes crossing a dilated, centrally-located bowel; (2) Large bowel obstruction, with peripherally located dilated bowel segments
Small bowel - >3cm = dilated. The valvulae conniventes run the whole way across the small bowel
Large bowel - >5cm = dilated. The haustra do not run the whole way across the large bowel.
Compare and contrast small to large bowel obstruction
Vomiting:
- Absent/faeculant in LBO
- Bilous in SBO
Constipation:
- Absolute in LBO
- May not be absolute in SBO
Progression:
- More rapid in SBO
The best differentitator is plain film radiograph of the abdomen
What is irritable bowel syndrome (IBS)?
IBS is a mixed group of abdominal symptoms for which no organic cause can be found. There may be differences in the ‘brain-gut’ axis, leading to increased visceral perception and decreased visceral pain threshold.
Describe the symptoms that may suggest a diagnosis of Irritable bowel syndrome (IBS)
- In the the preceding 12 months there should be at least 12 consecutive weeks of abdominal discomfort or pain, with 2/3 of the following features:
- Relieved with defecation
- Onset associated with a change in frequency of stool
- Onset associated with a change in form of stool
- Other symptoms:
- Bloating
- Passage of mucus
- Stool passage symptoms (tenesmus, feelings of incomplete evacuation)
- Associated gynaecological symptoms (dysmenorrhoea [painful periods]/dyspareunia [pain with sex]), urinary symptoms (frequency, urgency, nocturia) or back pain
It has prevalence of around 10-20%, with F:M >2:1, and onset before 40 years
Describe the epidemiology and risk factors for Crohn’s disease
- Prevalence of 50/100,00
- Male=Female
- Incidence peaks at 15-30, and also again in the 60s
Risk factors:
- Poor diet
- Family history
- Smoking
- Altered immune states
Describe the morphology and pathology of Crohn’s disease
I.e where in the body is affected? It appearance?
- Inflammation can affect any part of the GI tract (mouth to anus)
- Most commonly terminal ileum and ascending colon
- Can affect just one area, or multiple areas leaving normal bowel in between
- Skip lesions
- Involved bowel is narrowed due to the thickened wall, with deep ulcers
- ‘Rose-thorn ulcers’
- ‘Cobblestone’ appearance on CT (specific to Crohn’s, not seen on XR)
- Inflammation extends through all layers of the bowel
- Fistulae and stenosis are common
What are the clinical features of Crohn’s disease?
- Abdominal pain (varying character)
- Diarrhoea (steatorrhoea in ileal disease, bloody in colonic disease)
- Weight loss (or failure to thrive -FTT)
- Sever apthous ulceration of the mouth (early sign)
- Anal complications (fissure, fistula, haemorrhoids, skin tags, abscesses)
- Extra GI manifestations
- Can present with acute RIG pain/mass