Sports drinks are considered unsuitable for dehydration caused by vomiting and/or diarrhoea. This is because although sports drinks replenish electrolytes, they replace those lost through sweating, not through diarrhoea or vomiting. Also, sport drinks contain much more sugar than sodium which pulls more fluid into your intestines, worsening your dehydration. It’s a similar story for lemonade or other soft drinks. They have a high sugar content which attracts fluid into the gut, causing more diarrhoea. Juices containing a high amount of sugar also fall into this category so should be avoided during diarrhoea.