If you eat tomato and after digestion skin remains undigested will this cause disease?

No, consuming tomato skin will not cause disease.

The skin of a tomato is made up of cellulose, a type of dietary fiber that is indigestible by the human body. This means that it passes through the digestive system intact and is eventually excreted in the feces. While it is true that some people may experience discomfort or digestive issues after consuming tomato skin, this is usually due to the high fiber content of the skin, not because the skin is causing disease. In fact, dietary fiber is an important part of a healthy diet and can help to promote digestive health and regularity.