Imodium is a basic in many traveller´s medicine supply but remember that it only acts as a temporary “blockage” and is more suitable for having to travel while dealing with the symptoms.
If the cause of the disorder is bacterial, antibiotics such as Ciprofloxacin can help in severe cases but consulting a doctor first is advisable.
If you pass blood with the diarrhoea, have severe stomach cramps or fever over 38 °C it is important NOT to take any anti-diarrhoea medication and see a doctor as soon as possible.