The purpose of this study is to determine if EcoActive is safe and effective in people with Crohn's disease. EcoActive is a collection of bacteriophages. Bacteriophages (or phages) are viruses that infect only bacteria. The phages in EcoActive infect a specific type of bacteria called Adherent Invasive Escherichia coli (AIEC).

The cause of Crohn's disease is poorly understood. However, the presence of AIEC in the intestines is associated with worsening inflammation in this disease. Inflammation is the presence of redness, irritation, and ulcers in the intestines. By using phages that only infect and kill this specific type of bacteria (AIEC), it is the hope this can be used to improve the course of Crohn's disease. The phages would only target the AIEC, without affecting the natural, often helpful, bacteria of the intestines. EcoActive may also lessen the use of antibiotics to control symptoms. When antibiotics are used, they can have major effects on the rest of the bacteria in the intestines. Also, repeated use can cause intestinal bacteria to become resistant to antibiotics. Reduced use of antibiotics would limit both of these risks.