Four children in California have found out that drinking milk may not always be such a healthy option.

The children from San Diego, Riverside County, and San Bernardino County, all developed a serious case of diarrhea due to E coli after drinking non-pasteurized milk.

California authorities have now recalled the raw milk products, except for the butter and cheese, and has ordered the company, Fresno-based Organic Pastures, to stop making raw milk products until investigations have been completed.

Pasteurized milk, which is milk that has been cleared of bacteria, is far more common in California, but many people favour the use of raw milk products in the belief that it is healthier and more nutritious.

But many experts warn against the use of such products because of the danger of E coli contamination and say it is not worth the risk.

Although tests on the company’s products have failed to reveal the presence of the bacteria 0157:H7, which was found in the children, all the victims had consumed Organic Pastures products.

Organic Pastures owner Mark McAfee, says the recall is a precautionary measure which is understandable and says although they test their milk thoroughly, raw milk products have a long history of people becoming sick.

McAfee says lab tests have come back negative for E Coli and suggests the contamination might be due to raw hamburgers or even the contaminated spinach currently causing such a scare.

Advocates for raw milk say treating milk destroys beneficial micro-organisms that are good for digestion.

The Department of Food and Agriculture is investigating the outbreak and is advising people to throw out such recently purchased products.

Meanwhile, two of the four children, aged between seven and 10 years, remain in the intensive care unit.

The infection can cause abdominal pain and diarrhea with blood and although in most cases, the symptoms disappear within 10 days, in serious cases, kidney failure is also possible. Young children, senior citizens and pregnant women are more at risk.