I ended up switching rice ceral from breakfast to a dinner food. It was suggested to try and fill DD up so she slept better. I gave her fruit in the morning in stead, worked well for us. She was also a colic baby so the cereal at night was really good as heavy in her tummy, so did help in keeping her milk down.
The only issue I see with your bub Vickie is potential constipation. I like what the other mums suggested, maybe trying another food. To start with, mix it in with the cereal - then once bubs is going ok, just give the new food on its own.
Best of luck - sounds like your bub is taking to solids quite nicely.
DD is 3yr 8 months - DS is 6 months