My 6-year-old child has very aggressive behavior. He is very sweet and caring when he is in a great mood, but he loses his temper in few seconds. For example, when my 10-year-old son touches his things or even looks at his things, he becomes angry and starts screaming and abusing. He spits all the time, scratches with his nails, and uses abusive language all the time. I speak with him making him understand, but then he comes to hit me. He has had this behavior for the past two years. In school most of the time he is fine, but once in a while I do get complaints about his aggressive behavior.
We also started doing family meetings where we sit down every night to discuss and write about any unhappy or inappropriate behavior by any one of us and then everyone receives happy face if we did good deed and sad face if we hurt someone. And the rule is if we all get happy faces then is the time we can go eat food in a restaurant. But that doesn't seem to work either. My husband and I have done lots of talking with him about not using his hands and mouth to spit and saying dirty words, but he doesn't care about anything.
Physically he is very petite as per his age. He looks like a 4-year-old child. He has very bad eating habits as when he was young he had some issues with constipation and that's why he learned to hold his bowel movements. Because he started holding them he became less energetic, so I used to forcefully make him sit on the toilet, as I knew once he is on toilet he will pass his bowel right away. But sitting on the toilet was a big struggle. I used to also force him for food as he would not eat much until his movements are clear. We did lots of tests on him, but nothing could be found and doctors told me he would grow at a slower pace.
So now I don't force him for anything, understanding that he will use his own skill to understand his body and there won't be any struggles between us. So now he goes to toilet every 4-5 days and sometimes he eats great. The other times he doesn't eat for like 12-15 hours. I want to force him to eat, but at the same time I don't want to struggle with him. I think his aggressive behavior could also be due to our struggles.
What can be done to help him and me to change his behavior?