How can I alleviate my 10-month-old's constipation?

Fluids and fiber. The best way to prevent constipation is by including plenty of water, fruits, and high fiber foods in your infants diet. If your baby is constipated, try giving prunes, prune juice or pear juice. You can also call your doctor, he/she may recommend other over-the-counter stool softeners.
Fluids and fiber. Increase water and fluid content in diet. Encourage more fruits, vegetables, and roughage (fiber).