Disease is an abnormal condition that negatively affects the structure or function of part and all of the body of a living being. This disease is known as a medical condition associated with certain clinical signs and symptoms. Forward Chaining is a search technique that starts with known facts, then matches those facts with the IF part of IF-THEN rules. If there is a fact that matches the IF section, then
the rule is executed. There is also a problem in the research how the patient can validate the diagnosis of the disease. And the purpose of this study is to design an expert system to diagnose digestive diseases so that doctors can see an
accurate diagnosis. Patients can consult an expert or doctor first so that they know more clearly the symptoms of this digestive diseases