This sounds like an episode of food poisoning. If you were to have recurrent episodes, then we could look at IBS. In the meantime you may want to keep a food and symptom diary to see if it occurs again.

Diarrhoea can be caused by food poisoning, side effect of drug therapy, some bowel disorders. Once the bowel is upset, it then has problems digesting milk.

In relation to diarrhoea I recommend the following:
Avoid milk products for 24 hours
Drink plenty of water
Eat small bland meals
Eat fresh boiled rice as this slows down gastric transit

For adults use loperamide capsules 2mg, up to eight in 24 hours to stop diarrhoea. Cramping can be helped by dimethicone or peppermint oil capsules. Peppermint tea is really good to help settle the digestive tract.

Ensure you keep your fluid levels up. It should settle down in 24 - 48 hours however if you have been abroad recently, or there is blood, mucus or pus in the stool, then see a doctor sooner.

Regarding the nausea, using something like domperidone or metoclopramide will make you feel more comfortable. Sip water slowly and gargle with mouthwash to take away the taste.

Hope this information is useful