TV producer Clare Gilbert, 38, arrived in Mumbai for a two-week backpacking trip a couple of years ago and promptly came down with a nasty bout of diarrhoea

"I travelled with a girlfriend. We'd both been busy working right up to the day of departure and I'd just had my wisdom teeth out. Apart from buying a guidebook, we hadn't done much preparation.

"It was the first time I'd been to India and I suppose hygiene wasn't always at the forefront of my mind. I don't know where I caught the infection, but sometime the first day, I picked up a most unpleasant bug.

"The first night, I was going to the toilet every 20 or 30 minutes. My stomach hurt badly and I felt terrible. It was just as bad for my friend because she didn't get any sleep either. 

"I tried eating some papaya, which the hotel manager recommended, but it help. Nor did Imodium. I couldn't eat for two or three days, but I drank bottled water as often as I could. I gradually got better and we managed to continue our trip, even though I never felt completely well."

When she got back home to Devon, Clare continued to feel unwell for several weeks. A friend suggested that Clare may have developed long-term symptoms and she took a nutritional supplement that claims to rebalance the good and bad bacteria.  

"I've been back to India since then and was absolutely fine. I started to take a probiotic supplement before I left and was careful with what I ate and what I ate it off. I've learnt that, if you're careful, you can avoid diarrhoea. And it's certainly worth making the effort to take precautions."