If
vomiting is under control, then you can begin with clear fluids like coconut water, clear soups, lemon water with sugar. Give small frequent feedings to check the child's tolerance. Say 100 ml every 2 hours. If it is well-tolerated then you can progress to a full
liquid diet consisting of fruit juices like orange juice, pomegranate juice, pineapple juice with added sugar to provide instant energy. You can also give
glucose water at frequent intervals to meet energy needs. If
diarrhoea has subsided, then you can begin with curd/buttermilk and foods that are easily digestible. Avoid foods with spices and heavy seasonings especially those which can trigger vomiting sensation or cause diarrhoea. You can give boiled rice with pulses/chicken or fish. boiled eggs, bread with butter, bananas and cottage cheese or paneer.
Give more of starchy foods, sugar and jaggery to boost energy as the child must have become weak due to repeated episodes of vomiting and diarrhoea. Foods like rice, potatoes, colocasia or arvi (hindi), bread, glucose biscuits, semolina (sooji in hindi) pudding will give energy. Add some fats like butter and cow's ghee to cooked foods to increase energy intake.
Avoid giving harsh fibrous foods like chapatis, whole fruits like raw apples, strawberries, grapes etc. Apples can be given as applesauce (after cooking them as stewed apples. Remove skin from apples, give only pulp sweetened with sugar).
Frequent small feedings ensure better digestion without overtaxing the digestive system and will help in getting rid of weakness.
Adequate rest and a good night's sleep will aid in faster recovery.