10 Acute abdominal pain

Definitions
Abdominal pain is a subjective unpleasant sensation felt in any of the abdominal regions. Acute abdominal pain is usually used to refer to pain of sudden onset, and/or short duration. Referred pain is the perception of pain in an area remote from the site of origin of the pain.
KEY POINTS
The level of abdominal pain generally relates to the origin: foregut— upper; midgut—middle; hindgut—lower.
• Generally, colicky (visceral) pain is caused by stretching or contracting
a hollow viscus (e.g. gallbladder, ureter, ileum).
• Generally, constant localized (somatic) pain is caused by peritoneal
irritation and indicates the presence of inflammation/infection
(e.g. pancreatitis, cholecystitis, appendicitis).
• Associated back pain suggests retroperitoneal pathology
(aortic aneurysm, pancreatitis, posterior DU, pyelonephritis).
• Associated sacral or perineal pain suggests pelvic pathology
(ovarian cyst, PID, pelvic abscess).
• Generally, very severe pain indicates ischaemia or generalized
peritonitis (e.g. mesenteric infarction, perforated duodenal ulcer).
• Pain out of proportion to the physical signs suggests ischaemia
without perforation.
• Remember referred causes of pain: pneumonia (right lower lobe),
myocardial infarction, lumbar nerve root pathology.

KEY INVESTIGATIONS
• EBO: leucocytosis, infective/inflammatory diseases, anaemia, occult
malignancy, PUD.
• LETs: usually abnormal in cholangitis, may be abnormal in acute
cholecystitis.
• Amylase: serum level >1000 iu diagnostic of pancreatitis. Serum level
500—1000 iu, ?pancreatitis, perforated ulcer, bowel ischaemia, severe
sepsis. Serum level raised <500 iu, non-specific indicator of pathology.
• 3-HOG (serum): ectopic pregnancy.
• Arterial blood gases: metabolic acidosis—?bowel ischaemia,
peritonitis, pancreatitis.
• MSU: urinary tract infection (++ve nitrites, blood, protein), renal stone
(++ve blood).
• EGG: myocardial infarction.
• Chest X-ray: perforated viscus (free gas), pneumonia.
• Abdominal X-ray:
ischaemic bowel (dilated, thickened oedematous loops)
pancreatitis (‘sentinel’ dilated upper jejunum)
cholangitis (air in biliary tree)
acute colitis (dilated, oedematous, featureless colon)
acute obstruction (dilated loops, ‘string of pearls’ sign)
renal stones (radiodense opacity in renal tract).
• Ultrasound:
intra-abdominal abscesses (diverticular, appendicular, pelvic)
acute cholecystitis/empyema
ovarian pathology (cyst. ectopic pregnancy)
trauma (liver/spleen haematoma)
renal infections.
• OGD:
PUD, gastritis.
• CT scan:
pancreatitis, trauma (liver/spleen/mesenteric njuries), diverNcuhtis, leaking aortic aneurysm.
• IVU: renal stones, renal tract obstruction.

9 Vomiting

Definitions
Vomiting is defined as the involuntary return to, and forceful expulsion from, the mouth of all or part of the contents of the stomach. Waterbrash is the sudden secretion and accumulation of saliva in the mouth as a reflex associated with dyspepsia. Retching is the process whereby forceful contractions of the diaphragm and abdominal muscles occur without evacuation of the stomach contents.
KEY POINTS
• Vomiting is initiated when the vomiting centre in the medulla oblongata is stimulated, either directly (central vomiting) or via various afferent fibres (reflex vomiting).
• Vomiting of different origins is mediated by different pathways and transmitters. Therapy is best directed according to cause.
• Consider mechanical causes (e.g. gastric outflow or intestinal obstruction) before starting therapy.
Important diagnostic features
Central vomiting
• Drugs, e.g. morphine sulphate, chemotherapeutic agents.
• Uraemia.
• Viral hepatitis.
• Hypercalcaemia of any cause.
• Acute infections, especially in children.
• Pregnancy.
Reflex vomiting
Gastrointestinal causes (5HT3 and Ach mediated— treatment: promotilants, SHT3 antagonists)
• Ingestion of irritants.
Bacteria, e.g. salmonella (gastroenteritis).
Emetics, e.g. zinc sulphate, ipecacuanha.
Drugs, e.g. alcohol, salicylates (gastritis).
Poisons, e.g. salt, arsenic, phosphorus.

• PUD: especially gastric ulcer; vomiting relieves the pain.
• Intestinal obstruction.
Hour-glass stomach (carcinoma of the stomach). Pyloric stenosis—infant: hypertrophic pyloric stenosis, projectile vomiting; adult: pyloric outlet obstruction secondary to PUD or malignant disease.
Small bowel obstruction: adhesions, hernia, neoplasm, Crohn’s disease.
Large bowel obstruction: malignancy, volvulus, diverticular disease.
• Inflammation: appendicitis, peritonitis, pancreatitis, cholecystitis, biliary colic.
General causes (ACh and D2 mediated—treatment:
anticholinergics, antidopaminergics)
• Myocardial infarction.
• Ovarian disease, ectopic pregnancy.
• Severe pain (e.g. kick to the testis, gonadal torsion, blow to the
epigastrium).
• Severe coughing (e.g. pulmonary TB, pertussis).
CA’S causes UVAdr andACh mediated—treatment:
anticholinergics, sedatives)
• Raised intracranial pressure.
Head injury.
Cerebral tumour or abscess.
Hydrocephalus.
Meningitis.
Cerebral haemorrhage.
• Migraine.
• Epilepsy.
• Offensive sights, tastes and smells.
• Hysteria.
• Middle ear disorders (H2 mediated—treatment: antihistamines). Menière’s disease.
Travel/motion sickness.

8 Dyspepsia

Definition
Dyspepsia is the feeling of discomfort or pain in the upper abdomen or lower chest. Indigestion may be used by the patient to mean dyspepsia, regurgitation symptoms or flatulence.
KEY POINTS
• Dyspepsia maybe the only presenting symptom of upper Cl malignancy. All older patients and patients with atypical history should have endoscopy.
• In young adults, gastro-oesophageal reflux and 1-/elicobacter-positive gastritis are common causes.
• Dyspepsia is rarelythe only symptom of gallstones they are more often incidental findings.
Differential diagnosis
Oesophagus
• Reflux oesophagitis: retrosternal dyspepsia, worse after large meal/lying down, associated symptoms of regurgitation, pain on swallowing.
• Oesophageal carcinoma: new-onset dyspepsia in older patient, associated symptoms of weight loss/dysphagia/haematemesis, failure to respond to acid suppression treatment.
Stomach
• Gastritis: recurrent episodes of epigastric pain, transient or short-lived symptoms, may be associated with diet, responds well to antacids/acid suppression.

• Gastric ulcer: typically chronic epigastric pain, worse with food, ‘food fear’ may lead to weight loss, exacerbated by smoking/alcohol, occasionally relieved by vomiting.
• Carcinoma stomach: progressive symptoms, associated weight loss/anorexia, iron-deficient anaemia common, early satiety, epigastric mass.
Duodenum
• Duodenal ulcer: epigastric and back pain, chronic exacerbations lasting several weeks, relieved by food especially milky drthks, relieved by bed rest, commoner in younger men, associated with Helicobacter infection.
• Duodenitis: often transient, mild symptoms only, associated with alcohol and smoking.
Gallstones
Dyspepsia is rarely the only symptom, associated RUQ pain, needs normal OGD and positive ultrasound to be considered as cause for dyspeptic symptoms.

KEY INVESTIGATIONS
• EBO: anaemia suggests malignancy.
• OCD: tumours, PUD, assessment of oesophagitis.
• 24-hour pH monitoring: WORD.
• Ultrasound: ?gallstones.

7 Haematemesis

Definitions
GI bleeding is any blood loss from the GI tract (from the mouth to the anus), which may present with haematemesis, melaena, rectal bleeding or anaemia. Haematernesis is defined as vomiting blood and is usually caused by upper GI disease. Melaena is the passage PR of a black treacle-like stool that contains altered blood, usually as a result of proximal bowel bleeding.
KEY POINTS
• Haematemesis is usually caused by lesions proximal to the duodenojejunal junction.
• Melaena may be caused by lesions anywhere from oesophagus to
colon (upper Cl lesions can cause frank PR bleeding).
• Most tumours more commonly cause anaemia than frank haematemesis.
• In young adults, peptic ulcer disease (PUD), congenital lesions and
varices are common causes.
• In the elderly, tumours, PUD and angiodysplasia are common causes.
Important diagnostic features
Ocsophagus
• Reflux oesophagitis: small volumes, bright red, associated with regurgitation.
• Oesophageal carcinoma (rare): scanty, blood-stained debris, rarely significant volume, associated with weight loss, anergia, dysphagia.
• Bleeding varices: sudden onset, painless, large volumes, dark red blood, history of (alcoholic) liver disease, physical findings of portal hypertension.
• Trauma during vomiting (Mallory—Weiss syndrome): bright red bloody vomit usually preceded by several normal but forceful vomiting episodes.

Stomach
• Erosive gastritis: small volumes, bright red, may follow alcohol or NSAID intake/stress, history of dyspeptic symptoms.
• Gastric ulcer: often larger-sized bleed. painless, possible herald smaller bleeds, accompanied by altered blood (‘coffee
grounds’), history of PUD.
• Gastric cancer: rarely large bleed, anaemia commoner, associated weight loss, anorexia, dyspeptic symptoms.
• Gastric leiomyoma (rare): spontaneous-onset moderate-sized
bleed.
• Dieulafoy’s disease (rare): younger patients, spontaneous
large bleed, difficult to diagnose.
Duodenum
• Duodenal ulcer: past history of duodenal ulcer, melaena often
also prominent, symptoms of back pain, hunger pains, NSAID use.
• Aortoduodenal fistula (rare): usually infected graft post AAA
repair, massive haematemesis and PR bleed, usually fatal.

KEY INVESTIGATIONS
• FBC: carcinomas, reflux oesophagitis.
• LETs: liver disease (varices).
• Clotting: alcohol, bleeding diatheses.
• OCD: investigation of choice. High diagnostic accuracy, allows
therapeutic manoeuvres also (varices: injection; ulcers:
injection/cautery).
• Angiography: rare duodenal causes, obscure recurrent bleeds.
• Barium meal and follow through: useful for patients who are unfit for
OCD (respiratory disease) and ?proximal jejunal lesions.

MANAGEMENT
Minor bleed: Resusctaton Major bleed:
observation Continued resuscitation, urgent OCD
scheduled OCD _—
monitor haemoglobin and fluid balance. Peptic ulcer Varices Castritis
Endoscopic therapy Endoscopic therapy iv. PPI treatment
Re-bleed or high risk: surgery Sengstaken tube Early feeding
Surgery