The mouth, stomach, small intestine and large intestine together form the human digestive tract. The digestive system is responsible for absorbing food, breaking it down into nutrients, as well as absorbing them into the bloodstream and excreting non-digestible food components from the body. Interesting fact: The human digestive system is about 8 meters long. The surface area of the intestine is approximately 300 to 500 m2, which makes it the largest organ in the human body. There are numerous causes that can disrupt the digestive process. The most common illness is classic gastroenteritis, which causes diarrhea and vomiting. Irritable bowel syndrome (colon irritabile) is associated with abdominal cramps, bloating, diarrhea or constipation. In food intolerances, the digestion of certain nutrients is impaired. The best example here is lactose intolerance. In this case, the small intestine cannot properly utilize the supplied lactose due to an enzyme deficiency. The specialty for gastrointestinal diseases is called gastroenterology.