Yes, a 11-month-old baby who is constipated can be encouraged to drink more fluids to soften the stool. Adding more liquid to their cereal can also help. The use of PEG-3350 powder may be safe at this age, but it is important to consult a pharmacist or healthcare provider for proper dosing based on the baby's weight. If constipation persists or if there is a fissure present, it is recommended to seek medical evaluation and advice.