Hi M.,
My daughter was very sensitive to certain foods I ate, and she did not attempt to eat solids until about 8.5 to 9 months old. We breastfed exclusively as I knew formulas would've set her off! I wonder if you feel a desire to supplement with formula, or if it's an absolute need? Breastmilk would be great instead of formula, if possible.
After we started solids, for many of the solid foods I introduced to her, she would have a bad tummy for a few hours and then it would subside. It was awful and made us delay new solids as much as possible.
I have read on Dr Sears that babies can be allergic to things (specifically dairy) and then NOT allergic later. It is weird but it seems like that's what my daughter had. She would be sensitive/intolerant/allergic and then be fine the next time she tried the same food.
That made me wonder what indeed was the problem. I came to believe that she did not have the digestive enzymes to break down the food, and so she had bad stomach pains while attempting to digest. Then her stomach would learn how to make the enzymes to digest that food (because it had been introduced, her tummy got to work on producing the enzymes) and that would allow the next intake of that food to be OK.
I had heard this same thing because I'm vegetarian, and so my body doesn't make the enzymes needed to break down meats because they're not encountered by my digestive tract. If I were to eat meat, it would cause a stomachache because to my stomach, the meat is indigestible.
Long story short, I learned about full-spectrum enzyme tablets (mentioned by Adelle Davis) and also our local health food store advertises an enzyme supplement for babies' health. I would absolutely try this if I had another child with the same problem. By the time I'd researched far enough to learn about this, my daughter's trouble with it had subsided.
HTH!