Disgusting simulation reveals why you shouldn't drink expired milk and how it makes you sick

There's a saying about milk - if you have to smell it twice, it's probably off.

But let's face it, most of us have chanced a splash of milk we weren't 100 percent sure of - although we're not sure we would again after reading about what really happens when you consume spoiled dairy.

If you don't know Zack D. Films, he's a YouTuber who creates informative simulations about all kinds of interesting scenarios.

Expired milk can make you sick (Getty Stock Photo)

What happens when you drink expired milk?

In one video, he explained exactly why drinking off milk makes you sick, and what happens when it enters your digestive system.

Probably best to pause your dinner for this one.

"When you drink expired milk, it will make its way into your stomach and cause some nasty reactions," the video explains.

"The milk's acid bacteria produces a sour taste and a bad smell. Once in your gut, these bacteria multiply and your stomach sends signals to your brain that they need to be purged.

"Your body will do anything it can to get rid of the toxins including diarrhea, vomiting and intense abdominal pain."

People were disgusted after watching the clip, with one person commenting: "Thanks 4 showing this while I was eating."

While another said: "I find Zack's animations traumatizing, but still come back to watch them."

"This is why we should always check the expiration date," added a third.

While a fourth commented: "Even looking at expired milk makes my stomach feel nasty!"

Drinking off milk can lead to stomach cramps (Getty Stock Photo)

So, how do you know if milk is bad?

According to Medical News Today, spoiled milk will produce a sour smell which intensifies as time goes on.

"A yellowy color, crusts around the edges, and lumps in the milk also indicate that it is off," they explain.

"Drinking small quantities of spoiled milk can cause no symptoms or some minor symptoms, which will typically go away on their own. For example, it can cause stomach pain, nausea, diarrhea, or vomiting. Spoiled milk is unlikely to cause any long-term problems."

It's possible to keep milk fresher for longer by the way it's stored in your home.

For example, storing the milk in the fridge as soon as you get it home; making sure the lid is always secured on the bottle properly; keeping hot foods away from milk in the fridge; avoiding leaving the milk out of the fridge for long periods and ensuring the temperature of your refrigerator is sufficiently cool.