So, if your doctor tells you that you have diverticulitis, which means an infection within the diverticulum, the way to treat that is with antibiotics. So, the combination of two antibiotics and going on a low residual diet or clear liquid diet, you should be able to clear the infection within that diverticulum.
Now the problems occur if the antibiotics don't help to clear up the infection, and it could get into a bigger infection, in which case you would need IV antibiotics to help clear up the infection.
If that infection spreads outside the colon, you can develop diverticular abscesses, and in worse case scenarios, it can cause a tear called a diverticular perforation. In other cases, you can actually have some bleeding in which there's a blood vessel that runs along the diverticulum, and if there's enough infection and enough inflammation, there can be a small tear within the wall within that blood vessel, and cause diverticular bleeding.