My son continues to get what i think are small abscess on his lower abdomen but this time it is bigger & hurts with diarrhea. suggestions ?

Abscess: It can be one of the worst bacterial infections called mrsa. Your son needs to be seen by his pediatrician who will definitely do a culture to see what kind of infection it is. He might need antibiotics. Diarrhea can be a co-incidence or may be related to the infection. Start giving him pedialyte 4-6 ounces for each diarrhea..... But consult his pediatrician soon.