My boyfriend large intestine is swollen and is currently in the hospital being treated with antibiotics. Is this a condition that will reoccur?

Depends. It depends on the nature of the disease. If it is an infection due to an exposure to a bacterial pathogen, it will likely be fully treated with antibiotics. If it has another cause, such as structural or autoimmune, there may be recurrence. We would need more information to give a better answer.