Diarrhoea in Early Pregnancy: What to Know

Diarrhoea early in pregnancy is often linked to infection, food changes, or food intolerance, but dehydration and warning symptoms need prompt medical advice. Diarrhoea is not usually caused by pregnancy itself, so a new or persistent change in bowel movements deserves attention to its other possible causes. A short illness may settle with fluids and rest, while ongoing symptoms may need assessment and testing.

Loose or watery stools can happen after a stomach infection, including gastroenteritis or food poisoning. A recent change in diet, sensitivity to a food, or difficulty digesting a particular ingredient can also contribute; see Food Intolerance for background on this pattern. Less commonly, continuing diarrhoea may occur with conditions such as coeliac disease, Crohn's Disease, Irritable Bowel Syndrome, Giardiasis, or Hyperthyroidism. These possibilities cannot be distinguished from symptoms alone.

Pay attention to the whole picture: vomiting, abdominal cramps, fever, mucus or blood in the stool, recent travel, sick contacts, new medicines, and whether you can keep fluids down. Diarrhoea does not by itself show that there is a problem with the pregnancy, but losing fluid can make you unwell and may require treatment.

Take frequent small sips of water. An oral rehydration solution may help replace fluid and salts, especially if stools are frequent or vomiting is present; ask a pharmacist which product is suitable during pregnancy. Eat small, simple meals when you feel able, and avoid foods or drinks that clearly worsen the symptoms. Wash your hands carefully and avoid preparing food for other people if an infection is possible.

Do not start an anti-diarrhoea medicine, antibiotic, herbal product, or supplement without checking with a doctor or pharmacist because pregnancy can change which treatments are appropriate. Contact your maternity team, GP, or pharmacist if symptoms continue, return repeatedly, or make it difficult to eat and drink.

Seek urgent medical advice if you cannot keep fluids down, feel faint or confused, pass very little urine, have a very dry mouth, or notice worsening weakness. These can signal significant dehydration. Contact a healthcare professional promptly for blood or black stool, severe or localised abdominal pain, a high fever, repeated vomiting, or diarrhoea after recent travel or a course of antibiotics.

If diarrhoea occurs with vaginal bleeding, fluid leakage, severe pelvic pain, or any concern about your pregnancy, contact your maternity service urgently. If you are unable to reach them and symptoms are severe, use local emergency services.

Ask which fluids or rehydration products are suitable for you, whether a stool test is needed, and whether any medicine or supplement should be paused or changed. Tell them when the diarrhoea began, how often it is happening, what it looks like, whether you have vomiting or fever, and what you have eaten or taken recently. Mention travel, sick contacts, and any history of bowel or thyroid problems.