"...all doctors should be able to diagnose and treat nutritional deficiencies."

Royal College of Physicians. Nutrition and Patients: A Doctor's Responsibility. London 2002


This page has been printed from the www.stewartnutrition.co.uk web site.

Persistent Vomiting

This advice applies to those who are aged over 18 years.  There is a separate section for vomiting in pregnancy.

The majority of cases of short-lived vomiting are due to a viral illness or food poisoning and the presence of a bacterial toxin.  Initially other causes may need to be excluded and simple advice on possible causes and rehydration can be obtained from www.nhsdirect.nhs.uk

All patients with Persistent or continuous vomiting are recommended by NHS Direct to make an appointment to see their GP.

The Nutritional Consequences of Persistent Vomiting

Deficient Nutrient Consequences
Fluid Thirst, dry lips, reduced urine output, fatigue, rapid heart beat, increased fever, skin on the backs of the hands becomes loose, low BP collapse and confusion
Energy Fatigue, easily exhausted, confusion, low blood sugar
Sodium and Potassium Fatigue, muscle cramps, low blood pressure, rapid heart beat, collapse and confusion
Vitamin B1 – thiamin Fatigue, nausea, loss of appetite, muscle cramps, tingling in fingers, rapid heart beat, confusion, unsteadiness double vision and collapse

Nutrition support is most likely to be required by those who were underweight at the start of the illness, are rapidly losing weight as a result of the illness, the elderly, those with pre-existing medical problems especially heart, renal disease or diabetes, those who have had a high alcohol intake and those with anaemia or other known nutritional deficiencies. 

Nutritional Support for those with Persistent Vomiting


  • Take small frequent sips of water even if you don’t feel like it or are continuing to vomit
  • Try sipping diluted fruit juice – a source of potassium and sugar
  • Later on weak tepid tea with milk and added sugar or honey may be suitable

The tea may need to be without milk if there is associated diarrhoea or milk intolerance.


Eat easy-to-digest foods that contain carbohydrate and potassium:

  • Mashed potato
  • White bread with jam or honey
  • Ripe bananas, which can be mashed
  • Tinned fruit e.g. peaches
  • Stewed apple with added sugar
  • Vegetable soup with white bread/toast/crackers
  • Rice (though this is low in  potassium and vitamin B)

When the appetite has returned a simple diet emphasising the above foods, fortified breakfast cereals based on corn or rice and eggs, fish, and vegetables is usually appropriate.

Foods and Drinks to Avoid

Some foods can irritate the gut or are hard-to-digest and are best avoided during the convalescent period:

  • Fatty foods
  • Spicy foods
  • Grapefruit, orange, other acidic fruit, peppers and cucumber
  • Large amounts of red meat
  • Coffee and strong tea
  • Alcoholic drinks
  • Large amounts of pasta, white rice and noodles

The latter foods are notoriously low in potassium, magnesium and vitamin B1- thiamin.

Those who are at risk of nutritional deficiencies or are slow to recover from an illness characterised by vomiting may benefit from supplements of vitamin B e.g. Vitamin B Compound Strong or a Vitamin B Complex 5-10 mg two or three times daily after food or Sanatogen Berocca half an effervescent tablet two to three times daily.

If a low serum potassium level is found then potassium-rich fruits and vegetables should be emphasised.

Poor intakes of potassium are not uncommon in the normal “healthy” population as in the National Diet and Nutrition Surveys they were recorded in 6% of men and 19% of women aged 19 to 64 years and in 17% of free-living men and 39% of free-living women aged 65 years and older.

Copyright Dr. Alan Stewart M.B.B.S.M.R.C.P. (UK)M.F. Hom.
47 Priory Street, Lewes, East Sussex. BN7 1HJ
Tel 01273 487003 Fax: 01273 487576