My eight month old son has little red bumps on his stomach what are they?

Rashes. It is difficult to answer your question. There are several causes for what you have described and it is difficult to make a diagnosis without looking at the rash itself. If your son is experiencing any other discomfort such as a fever, itching, or irritability, you should take your child to your pediatrician. Most causes of what you describe are nothing to worry about, but it should be evaluated.
Abdominal rash. Rashes are notoriously difficult to diagnose without being seen. Have pediatrician exam the child. May be simple prickly heat rash, diaper rash, viral illness, or any number of causes. Keep child comfortable with infant's tylenol (acetaminophen) if fever over 101?f & keep well hydrated with fluids.

Related Questions

My 20 month old is scratching her back and stomach. It looks like she has small red bumps that go away, but she sometimes leaves scratch marks on her?

Fabric or irritant. She is having something that is irritating and inflaming her skin. Could be fabrics and detergent, or grass and pollen if she's been outside. Cool compresses, vaseline, and baking soda/ aveeno (oatmeal) baths are very soothing. Hydrocortisone cream can help with the itching also. If it doesn't resolve discuss it with your doctor. Read more...
Keep nails short. Keeping her nails short can help prevent the scratches, but that doesn't take care of what's causing her red bumps. Those could be insect bites, or hives, or molluscum contagiosum, or viral infection, etc. Read more...