How can I differentiate between nausea and vomiting caused by gastrointestinal issues versus other underlying conditions?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 14 August 2025Updated: 14 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Differentiating between nausea and vomiting caused by gastrointestinal (GI) issues versus other underlying conditions involves a comprehensive assessment of the person's history, a physical examination, and relevant investigations .

  • Gastrointestinal Causes:
    • Gastric Stasis: Features include a large volume of vomitus, infrequent vomiting, relief of symptoms after vomiting, oesophageal reflux, epigastric fullness, early satiation, and hiccups . A succussion splash may be present .
    • Gastric Outflow Obstruction: Symptoms are similar to gastric stasis but also involve forceful vomiting and rapid dehydration .
    • 'Squashed Stomach Syndrome': This presents with symptoms similar to gastric stasis but with low-volume vomiting .
    • Oesophageal Blockage: Vomiting occurs soon after eating or drinking, the vomitus comprises what has just been swallowed, and there is a sensation of food sticking .
    • Bowel Obstruction: Characterised by intermittent nausea (often relieved by vomiting), worsening nausea and/or faeculent vomiting as the obstruction progresses, abdominal pain (which may be colicky), and abdominal distension (though this may be absent in high obstructions) .
    • Other GI Indicators: Bile-stained (green or yellow-green) vomit may suggest intestinal obstruction . Haematemesis (blood in vomit), excluding swallowed blood, can indicate a serious bleed from the oesophagus, stomach, or upper gut . Blood in the stool may suggest conditions like bacterial gastroenteritis or an acute surgical condition . Abdominal distension, tenderness, or a palpable mass can suggest intestinal obstruction or another acute surgical condition .
    • Suspected GI Cancers: Consider oesophageal or stomach cancer if there is nausea or vomiting with weight loss, or with a raised platelet count, reflux, dyspepsia, or upper abdominal pain, especially in individuals aged 55 and over . Pancreatic cancer should be considered if nausea or vomiting occurs with weight loss in individuals aged 60 and over .
  • Other Underlying Conditions:
    • Increased Intracranial Pressure: Vomiting is often effortless, occurs frequently in the morning, and may be associated with a diurnal headache and papilloedema . Nausea may also be diurnal . Altered responsiveness, such as lethargy or irritability, can also be a sign .
    • Motion-Associated Emesis: Nausea and/or sudden vomiting may occur on movement, such as turning in bed .
    • Anxiety-Related Nausea: Nausea presents in waves, may be triggered by a previously experienced stimulus, and can be relieved by distraction .
    • Chemically Induced Nausea: This typically presents as constant nausea with variable vomiting . This can be due to drugs (e.g., opioids, digoxin, antibiotics), metabolic causes (e.g., hypercalcaemia, uraemia, renal failure, tumour toxins), or intracranial disease .
    • Infection: Appearing unwell or having a fever may suggest an infection . Dysuria can indicate a urinary tract infection (UTI) . UTIs can also be a cause of late-onset vomiting .
  • General Assessment for Differentiation:
    • History: Ask about the onset, frequency, intensity, relieving and exacerbating factors of nausea, and its relationship to vomiting . For vomiting, inquire about its onset, frequency, quantity, force, colour, timing, and pattern . Also, ask about other symptoms like dyspepsia, heartburn, constipation, diarrhoea, headache, or confusion . Review the person's medication history, including recent changes and the use of anti-emetics .
    • Examination: Perform a general examination to look for signs of dehydration, infection, confusion, drowsiness, or weakness . Assess the oral cavity, examine the abdomen for tenderness, swelling, distension, or signs of intestinal obstruction, and perform a rectal examination if faecal impaction is suspected . If increased intracranial pressure is a possibility, check the fundi for papilloedema .
    • Investigations: Blood tests to exclude hypercalcaemia or uraemia are often useful . Other helpful blood tests include liver function tests and blood glucose levels . Consider tests to exclude a urinary tract infection .

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