UK holidaymakers are being warned about a nasty infectious disease called cyclosporiasis that can cause explosive diarrhoea, after a sharp rise in cases.
The UK Health Security Agency (UKHSA), external said 67 cases have been reported since April, with many of them among travellers returning from Mexico.
It comes amid an outbreak in the US that has infected more than 18,000 people across 45 states. The source hasn't been identified yet and there have been no reported deaths.
The illness is caused by a parasite, cyclospora, that can contaminate food like salads, herbs and soft fruits. It doesn't naturally occur in the UK and there is no risk of spread from person to person, experts stress.
Between 30 April and 15 July 2026, 30 cases have been reported in England, 27 in Scotland and 10 in Wales, according to the UKHSA.
Of the 52 cases with travel information available, 48 reported having travelled to Mexico, with many saying they had stayed in either the white sand beach resort area of Riviera Maya, or slightly north of there in coastal Cancún.
The UKHSA said those affected reported staying in "a range of different hotels and consuming a variety of different food and drink within their resort as part of an all-inclusive holiday package".
There are ongoing investigations and monitoring of the situation.
People can protect themselves while away by following good food and water hygiene measures, including drinking bottled water and eating thoroughly cooked food, even when staying in high-end all-inclusive resorts.
Experts also advise people avoid certain foods such as fresh uncooked berries and herbs, unpeeled fruit and salad items.
'Like you have a balloon in your stomach'
Some who have been struck by it describe having to use the toilet up to 20 times a day, due to the frequent and explosive nature of the watery diarrhoea that's the main symptom.
The intestinal illness has recently affected thousands of people in the US.
Nick Palmiter, who is 29 and from Monroe County in Michigan, told the BBC he experienced feeling constant pressure and bubbling, "almost like you have a balloon in your stomach".
Although most cases resolve on their own, antibiotics can be given to treat severe or prolonged infections.
The UKHSA said it anticipates there will be more cases linked to increased summer travel to Mexico and possibly the US too.
Dr Philip Veal from the agency said: "If you develop symptoms after returning from travel, such as watery diarrhoea, loss of appetite, weight loss, stomach cramps or pain, bloating, increased wind, nausea, fatigue or other flu-like symptoms, please seek medical attention and inform your healthcare professional of your travel history."
