Colorectal Surgery JC053: Lower And Diffuse Abdominal Pain: RLQ Problems, Pelvic Inflammatory Disease, Peritonitis And Abdominal Emergencies

Question 1

Origin of abdominal pain

Answer 1

1. Visceral pain
   - stretching of hollow / solid organ (e.g. by distension, foreign body)
   - **Dull + **Vaguely localised (∵ visceral pain fibre stimulated)
   - location related to **embryonic origin of organ
   —> Foregut (stomach, biliary tract, D1, D2): **Epigastric pain
   —> Midgut (D2 to proximal 2/3 transverse colon): **Periumbilical pain
   —> Hindgut (distal 1/3 transverse colon to rectum): **Hypogastric pain
2. Parietal pain
   - irritation of pain fibres of **Parietal peritoneum (e.g. by inflammation, blood)
   - **Sharp
   - localised to ***Dermatome at site of stimulus
   - e.g. Appendicitis

Question 2

Describing the pain

Answer 2

1. Location
   - localised
   - diffuse
   - vague (fail / reluctant to describe location)
2. Onset
   - sudden
   - gradual
3. Severity
   - mild
   - excruciating
4. Character
   - **colicky (pain / spasm resulting from contraction of hollow organ against an obstruction e.g. **Biliary tract, Ureter, Small / Large intestine)
   - persistent
   - dull / sharp
5. Duration
6. Aggravating / Relieving factors
7. Radiation / Shifting / Referred pain
8. Symptoms associated with pain

Question 3

***Location of pain

Answer 3

1. RLQ (Colon, Appendix, Terminal ileum, Urogenital organs, Ovary, Hernia)
   - **Acute appendicitis
   - **Mesenteric adenitis
   - **Caecal diverticulitis
   - **Meckel’s diverticulitis
   - ***Ureteric Colic
   - Ruptured ectopic pregnancy
   - Ovarian cyst torsion
   - Ileitis
   - Ca colon
   - Inguinal / Femoral hernia
   - Testicular pathology
   - Cholecystitis (distended gallbladder)
2. LLQ
   - **Sigmoid diverticulitis
   - **Ca sigmoid
   - Ureteric Colic
   - Ruptured ectopic pregnancy
   - Ovarian cyst torsion
   - Inguinal / Femoral hernia
   - Testicular pathology
3. Periumbilical pain
   - **Small bowel IO
   - **GE
   - Early acute appendicitis
   - **Bowel ischaemia
   - IBS
   - **Ruptured AAA
   - ***Acute pancreatitis
4. Hypogastrium
   - **Large bowel IO
   - Cystitis
   - **Pelvic inflammatory disease
   - Urinary retention

Question 4

Radiation / Shifting / Referred pain

Answer 4

Radiation:
- pain spread from one site to another
- e.g. ***Pancreatitis, Ruptured AAA —> Back
- e.g. Ureteric pathology —> Ipsilateral testicular region
- e.g. Testicular —> Ipsilateral loin region

Referred pain:
- pain felt at a site different from stimulus / pathology
- e.g. **Liver abscess —> right shoulder tip
- e.g. **Cholecystitis —> right scapula tip

Shifting pain:
- pain shifts from one site to another with time
- e.g. ***Acute appendicitis —> Periumbilical to RLQ

Question 5

***Associated symptoms and History

Answer 5

1. ***Vomiting, Diarrhoea
   - GI pathology
2. Abdominal distension
   - ***IO
   - Peritonitis —> Paralytic ileus
3. Fever
   - Infection
4. ***Dysuria, Haematuria
   - Urogenital pathology
5. ***Rectal bleeding / Mucus
   - Rectal pathology (benign / malignant) e.g. Colitis, Proctitis
6. ***Change of bowel habit
   - Colorectal malignant / inflammation e.g. Colitis
7. Vaginal discharge
   - Gynaecological pathology
8. Loss of appetite, Weight change
   - Malignancies
   - Benign: TB peritonitis, TB bowel
9. Family history
   - Colorectal malignancies
10. Surgical history
    - Appendectomy
    - Abdominal surgery
11. Menstrual history
    - Gynaecological pathology e.g. Cyclical?, Chance of pregnancy
12. Sexual history

Question 6

Physical examination

Answer 6

1. General
   - Fever
   - Vital signs: Temp, BP, Pulse, RR
   - Hydration status
2. Abdomen
   - **Distension (symmetrical / asymmetrical)
   - **Tenderness, Guarding, Rebound tenderness (Peritoneal signs)
   - **Mass (on deep palpation)
   - **Bowel sound (hyperactive / hypoactive)
   - Hernia (cough impulse)
   - Scars
3. Rectal + Vaginal examination (+ Urine dipstix + External genitalia)

Question 7

***Investigations

Answer 7

1. Bedside tests
   - **Urinalysis (Urine R/M: UTI, Microscopic RBC)
   - **Pregnancy test
2. Blood tests
   - CBC + D/C (e.g. **Leukocytosis in strangulation, ischaemic bowel, diverticulitis, acute appendicitis, peritonitis)
   - LRFT
   - Electrolytes
   - **Amylase (acute pancreatitis)
   - **ABG (bowel ischaemia: metabolic acidosis, vomiting: alkalosis)
   - **VBG (lactate)
   - Clotting profile (planning for invasive procedures)
   - Type and screen (planning for invasive procedures)
3. Imaging
   - Erect CXR (pneumoperitoneum / free gas under diaphragm: perforated viscus)

• **Erect + Supine AXR
  —> **free gas (pneumoperitoneum)
  —> **dilated bowel (e.g. massive dilatation of colon)
  —> **air-fluid levels
  —> **evidence of strangulation:
  ——> thumb printing (large bowel wall thickening)
  ——> pneumatosis cystoides intestinalis (presence of multiple gas-filled cysts in submucosa / subserosa of the small intestine, signify necrotising enterocolitis, impending bowel perforation)
  ——> free peritoneal gas
  —> **air in biliary tree
• USG (pelvis)
• CT (more sensitive than AXR)
  —> **level of obstruction (transition between dilated and collapsed loop)
  —> lesions (tumour, foreign body)
  —> **viability of bowel (by IV contrast)
• Contrast studies
  —> water soluble contrast
  —> differentiate complete vs partial obstruction
  —> Ba study: precipitate complete obstruction + barium peritonitis
  —> therapeutic effect?

4. Endoscopy
   - Colonoscopy
   - Upper endoscopy

Question 8

Common causes of Lower abdominal pain

Answer 8

1. Acute appendicitis
2. Mesenteric adenitis
3. Ureteric colic
4. Diverticulitis
5. Ileitis
6. Meckel’s Diverticulum
7. Torsion of testis
8. Ectopic pregnancy
9. Pelvic inflammatory disease
10. Torsion / Ruptured ovarian cyst
11. Large bowel obstruction
12. Ischaemic bowel

Question 9

1. Acute appendicitis

Answer 9

• less common in elderly

S/S:
- Shifting pain: Periumbilical (visceral pain) —> RLQ (somatic pain)
- Localised tenderness + ***Guarding at McBurney’s point (1/3 from ASIS to umbilicus)
- N+V, Loss of appetite, Diarrhoea, Dysuria, Fever
- Gradual onset (within a few days)
- Flank pain (26% of appendix are retrocaecal), RUQ pain (4%) (SpC Revision)
- Rovsing’s sign, Psoas sign, Obturator sign (SpC Revision)

Investigations:
- AXR
—> Appendiceal faecalith / gas
—> Localised ileus
—> Blurred right psoas muscle
—> Free air

• CT scan:
  —> Pericaecal inflammation, abscess
  —> Periappendiceal phlegmon
  —> Fluid collection, localised fat stranding

Diagnosis:
- **Clinical
- **Ultrasound + CT scan may be helpful (sensitivity at most 90%)
- Blood tests: ***Leukocytosis

Algorithm (SpC Revision):
- Clinical appendicitis —> Call surgeon
- Maybe appendicitis —> CT
- Unlikely appendicitis —> observe for 6-12 hours / re-examine after 12 hours

Treatment:
- Analgesia
- **Antibiotics (early uncomplicated case) (Tazocin: cover anaerobes, gram -ve, enterococci)
- **Appendicectomy (Laparoscopic vs Open)

Question 10

2. Mesenteric adenitis

Answer 10

• often misdiagnosed at Acute appendicitis
• usually in ***children
• Causative organisms: β-haemolytic Strept, E. coli, Strept viridans, Yersinia, Coxsackievirus, Rubeola virus, Adenovirus

S/S:
- **Sore throat + High fever (Recent)
- **Not much peritoneal sign
- Presence of ***enlarged LN at terminal ileum found during operation

Diagnosis:
- CT scan
- during Laparotomy / Laparoscopy for suspected acute appendicitis

Question 11

3. Ureteric colic

Answer 11

• Presence of stones in R/L Ureter

S/S:
- **True colic, Spastic, Severe, Gripping in nature
- starts at Loin —> **radiate to Groin
- ***RBC in urinalysis

Diagnosis:
- X-ray
- Plain CT abdomen

Treatment:
- Conservative
- Pain relief: majority of stones pass spontaneously

Question 12

4. Diverticulitis

Answer 12

Colonic diverticula: outpouchings of colon where mucosa herniate through muscular wall
- Diverticulitis: **microperforation
- usually at site where blood vessels penetrate bowel wall
- most common in **Sigmoid (Asians: more **right sided diverticula)
- 60% elderly over 80
- majority **asymptomatic
- Severity from **Diverticulitis —> **Localised diverticular abscess —> **Purulent peritonitis —> **Faecal peritonitis

S/S:
- Localised Fever, Tenderness, Guarding
- **Leukocytosis
- **Abscess formation, ***Peritonitis
- Change in bowel habits
- Urinary symptoms
- Tenesmus
- Paralytic ileus
- SBO

Diagnosis:
- CT scan (diagnosis + assess severity)
—> Mural thickening
—> Presence of diverticula
—> ***Collection with contrast enhancement (Peridiverticular abscess), free gas etc.
—> Pericolic fat stranding
—> Thickened bowel wall

Treatment (depend on severity):
- ***Antibiotics (Simple diverticulitis)
- Image-guided drainage (Localised diverticular abscess)
- Laparoscopy + Lavage (Purulent peritonitis)
- Laparotomy + Bowel resection (Faecal peritonitis)

Question 13

5. Ileitis

Answer 13

• Sometimes misdiagnosed with Acute appendicitis
• Incidental finding of ***inflamed terminal ileum during operation

Causes:
- **Crohn’s disease
- **TB
- ***Bacterial infection (e.g. Campylobacter, Yersinia, Salmonella)
- Radiation enteritis

Question 14

6. Meckel’s Diverticulum

Answer 14

• Remnant of omphalo-mesenteric (vitelline) duct
• Apex / Fibrous cord adherent to umbilicus
• May contain ***ectopic gastric / pancreatic mucosa (Meckel’s scan)

Rule of “2”:
- 2% population
- ***2 feet from ileocaecal valve
- 2 inch long
- presents at 2 yo

S/S:
- Bleeding, Perforation (Meckel’s diverticulitis), **Volvulus, **Intussusception
- ~ to Acute appendicitis

Diagnosis:
- CT scan
- Incidental finding during appendicectomy

Treatment:
- **Antibiotics
- **Diverticuloectomy / Small bowel resection

Question 15

7. Torsion of testis

Answer 15

Commonest age: ***10-15

S/S:
- Severe pain in testis and groin
- Preceded by vague abdominal pain
- Could radiate to ***loin

Examination:
- Tender + ***High lying tests

Treatment:
- **Surgical exploration +/- **Orchidopexy +/- ***Orchidectomy

DDx:
- ***Epididymo-orchitis
- Testicular tumour

Question 16

8. Ectopic pregnancy

Answer 16

• Fertilised ovum implants outside uterus
• Most common site: Fallopian tube
• Causes rupture at ***6 week
• Higher risk in previous ***PID, Ectopic pregnancy

S/S:
- Dizziness, Fainting, Low BP, **Shock
- **Sudden severe pain, ***bleeding, circulatory collapse

Investigations:
- ***Pregnancy test (hCG may not be high enough to be positive)
- CBC
- Type and screen

Diagnosis:
- ***USG

Treatment:
- **Large bore IV cannula + **Resuscitation
- Urgent laparoscopy + ***Salpingotomy / Salpingectomy

Question 17

9. Pelvic inflammatory disease

Answer 17

• Commonly affects age <40
• ***Ascending infection from vagina
• History of gynaecological procedure, IUCD, STI
• ***Chlamydia trachomatis / Neisseria gonorrhoea

S/S:
- **High fever
- Lower abdominal pain
- **Dysuria
- **Dyspareunia (pain during sex)
- **Vaginal discharge
- Cervical excitation

Treatment:
- Antibiotics
- Drainage of ***tubo-ovarian abscess (image guided / laparoscopic)

Question 18

10. Torsion / Ruptured ovarian cyst

Answer 18

S/S:
1. Ovarian cyst complications
- **Ruptured
- **Torsion
- ***Infarct

2. Lower abdominal pain +/- Tenderness / Guarding

Diagnosis:
- USG / CT

Treatment:
- Laparoscopy ovarian **cystectomy / **oophorectomy

Question 19

11. Large bowel obstruction

Answer 19

Common causes:
1. **Ca colon
2. **Volvulus
3. Diverticular stricture
4. Pseudo-obstruction

S/S:
- **Cramping pain
- **Vomiting
- **Abdominal distension
- **Constipation

P/E:
- Hydration status
- **Tachycardia / Hypotension
- **Abdominal distension + tenderness + mass
- Hernia orifices
- **Bowel sounds
- **Rectal examination (Rectal collapse vs Rectum still have space in pseudo-obstruction)

Investigations:
1. Blood tests
2. **AXR
- Small IO: Valvulae conniventes, Central
- Large IO: Haustra, Peripheral
3. CT
- level of obstruction (transitional zone from dilated to collapse)
- cause
- **viability of bowel
- presence of metastasis if malignant cause
4. Contrast study
- gastrografin follow through / enema

Treatment (記: NNF):
- Adhesion IO (resolve on its own)
1. **Nil per oral
2. **NG tube decompression
3. ***Fluid resuscitation

***Definitive treatment:
1. Colonic stenting
2. Endoscopic decompression
3. Bowel resection
4. Stoma

Question 20

12. Ischaemic bowel

Answer 20

• High risk of mortality
• Often delayed diagnosis
• Elderly, history of AF / IHD

Mechanism:
- **Thromboembolism
- **Venous occlusion
- ***Non-obstructive mesenteric ischaemia (when Hypotension)
- Chronic mesenteric ischaemia
- Mechanical (Volvulus, Hernia)

S/S:
- **Constant severe non-specific abdominal pain (Disproportionate to signs found)
- **Little peritoneal signs
- Rectal bleeding / bloody diarrhoea
- Ileus —> ***Distension

Investigations:
- Leukocytosis
- ***Metabolic acidosis
- Renal failure
- Mesenteric / CT angiography (SpC Revision)

Treatment:
- Resuscitation
- ***Resect non-viable bowel

Question 21

Diffuse abdominal pain

Answer 21

1. ***Peritonitis
2. ***Central abdominal pain
3. Vaguely localised abdominal pain
4. ***Non-specific abdominal pain (e.g. GE)

Question 22

***Peritonitis

Answer 22

• Inflammation of Peritoneum
• One of commonest surgical ***emergency

Classification
1. Localised (e.g. ruptured acute appendicitis) / Generalised / Diffuse
2. **Bacterial / **Chemical (e.g. bleeding, urine, bile, pancreatic juice, gastric juice)
3. **Primary (e.g. infection, ascites, CAPD peritonitis) / **Secondary (e.g. most common perforated GU, DU, bowel, acute appendicitis) / Tertiary (decreased in host immune response after treated peritonitis —> superimposed infection by opportunistic organism)

Causes:
- **Infection (most common)
—> Primary bacterial peritonitis
—> Secondary bacterial peritonitis
- **Bleeding
- Urine
- Bile
- Pancreatic juice
- Gastric juice

S/S:
- S/S of primary pathology
- **Burning pain (initially localised —> later spread)
- **Exacerbation of pain by movement / coughing
- **Tenderness, Rebound, Guarding
- **Absence of bowel sound (Paralytic ileus)
- Fever, Tachycardia, Tachypnea
- ***Septic shock

Investigations:
1. ***Peritoneal fluid analysis

Question 23

***Primary bacterial peritonitis

Answer 23

Causes:
1. **Spontaneous bacterial peritonitis (SBP)
2. **Tuberculous peritonitis
3. ***CAPD peritonitis

• Usually ***Monomicrobial (vs Secondary: Polymicrobial)
  —> Strep. pneumoniae
  —> Group A Strept
  —> Enteric organisms
• Risk factors (ascites, malnutrition, intra-abdominal malignancy, immunosuppression, splenectomy, chronic liver / renal disease)

Question 24

Peritoneal fluid analysis

Answer 24

1. Character
   - serous
   - blood-stained
   - **purulent
   - **bile-stained
   - ***faeculent
2. Cell counts
   - ***neutrophil >500 —> bacterial
3. Glucose, Protein, LDH
   - **low glucose, **high protein, ***high LDH (compared to serum) —> bacterial
4. Gram stain
5. Culture
   - aerobic
   - anaerobic
   - AFB
   - fungal
6. ***Amylase
   - pancreatitis
   - pseudocyst
7. ***Creatinine
   - urine

Question 25

Tuberculous peritonitis

Answer 25

- rare in developed countries - presentation may be non-specific S/S (subtle): - Insidious onset of abdominal pain - ***Low-grade fever - Weight loss - Peritoneal sign not florid - Mimic malignancy (***ascites, ***thickened peritoneum, weight loss) Diagnosis (difficult): - Laparoscopy - ***Biopsy of peritoneum - AFB smear of peritoneal fluid often negative, culture take 4-6 weeks but still negative

Question 26

***Acute secondary bacterial peritonitis

Answer 26

- ***Most common type of peritonitis - Localised (e.g. intra-abdominal abscess) / Diffuse - could be Preceded by ***Chemical peritonitis (e.g. gastric juice, bile, pancreatic juice, urine, blood) Causes (記: Perforation, Inflammation, Ischaemia): 1. ***Severe inflammation of abdominal organ (e.g. Diverticulitis, Cholecystitis, Appendicitis) 2. ***Perforation of GI tract (spontaneous / trauma / iatrogenic) 3. Anastomotic leakage 4. ***Ischaemia of abdominal organ (e.g. bowel) ***Polymicrobial: - Gram -ve: E. coli, Enterobacter, Proteus, Pseudomonas - Gram +ve: Streptococci, Enterococci - Anaerobes: Bacteroides Treatment: 1. General - ***IV fluid replacement - ***NG tube to decompress / Urinary catheter / Oxygen - Pain relief - ***Broad spectrum antibiotics - Close monitoring for change of condition (e.g. vitals, hydration status) 2. Definitive (Treat according to cause) - ***Drainage: Percutaneous / Surgical drainage of abdominal abscess - Operation —> ***Laparoscopic surgery / Laparotomy —> PPU repair, Cholecystectomy, Bowel resection

Question 27

Why is peritonitis dangerous?

Answer 27

Pathology: - Peritoneum become ***edematous, hyperaemic, covered with fibrinous exudates —> ***Sequestration of large amount of protein rich fluid —> ***Circulatory collapse, ***Septicaemia, ***Endotoxaemia —> ***Hypovolaemia + ***Septic shock

Question 28

Peritonitis in elderly

Answer 28

- Poor historian, confused / dementia - History inaccurate (rely on care-provider) - Peritoneal signs may be mild - High index of suspicion —> ***Abdominal pain, Abdominal distension —> ***Fever, ***Leukocytosis, ***Acidosis, ***Sepsis of unexplained cause

Question 29

Other easily missed conditions

Answer 29

1. Hernia: Inguinal, Femoral 2. Ruptured AAA / Aortic dissection - ***tearing pain at epigastrium radiate to back - pulsatile mass at epigastrium - ***shock 3. Herpes zoster (severe abdominal pain without any other signs) - ***dermatomal hyperaesthesia - vesicular eruption (late presentation) 4. Pancreatitis - check amylase 5. Retention of urine - ***no peritoneal sign, all other signs normal - pelvic mass palpable (***distended bladder) - bowel shadow at upper abdomen (on AXR) 6. Non-specific abdominal pain - longer onset / duration - no definitive cause identified - no other associated symptoms

Question 30

General Pre-operation considerations (SpC Revision)

Answer 30

Depends on indications: 1. Consent 2. Preop workup - Disease staging - Localization - Cardiopulmonary reserve 3. Blood tests including T/S 4. Correct dehydration, anaemia, malnutrition 5. Antibiotic prophylaxis (2nd cephalosporin, metronidazole) 6. Bowel preparation (PEG) 7. Stoma siting 8. Selective decontamination of digestive tract (SDD) 9. DVT prophylaxis 10. NG tube insertion (EOT, decompress stomach) 11. Foley insertion (decompress bladder, monitor urine)