N.J.
Hi M.,
Check if the food you are giving her is making her constipated? Keep a track of what you are feeding her and you should be able to see a pattern (rice cereal, banana, apple are general culprits). I would also definitely add water to the diet- up until now, breast milk provided enough water for her, but since she has weaned off, you should give her more water. Instead of giving formula after a meal, I would give water. It might be also be that you are feeding her too much? Try reducing the portions and see if that makes a difference. Also make sure she is active after a meal (make her stand, let her crawl/walk/cruise)- activity helps with digestion.
Final advice, try gripe water (make sure its without alcohol)- little remedies makes it. Its herbal -aids with digestion and is great for teething as well.
Good luck! I hope your little one feels better soon.