Given below are some of the common medical conditions that affect the digestive system. There are many other diseases and disorders that can affect the digestive system. If you go through the list of common infectious diseases, you can come across numerous conditions related to this system.They include cholera, typhoid fever, staphylococcal food poisoning, bacillary dysentery, and salmonellosis.ommon Digestive Diseases. As mentioned above, the organs of the digestive system may develop different medical conditions. While some of them affect a particular organ or a part of that organ, some others affect more than one organ of the system.