Thank you for your query.
occuring while going to your home town can be because of the water supply or hygienic conditions. Kindly ensure that you consume boiled and cooled water only. Kindly ensure that the food that you consume is cooked hygienically.
There is no vaccine to prevent diarrhoea unless it is due to cholera
or salmonella infection
in which case you can take cholera vaccine and/or typhoid vaccine
Diarrhoea is not going to interfere with conception. You have to ensure that you take advantage of your ovulation dates to conceive.
Wishing you all the best,