Hello...
In this period bay have tendency to pass frequent stool because of un maturated intestine, or some time they are not passed stool more than 2 days also, and this is normal.

Your baby is already 7 month old so you can go for weaning (complementary food )

Weaning:
Biscuits in milk
Mashed banana/potato
Any cereal may be mixed with water or milk
Mashed and boiled Vegetable
Boiled or Half Boiled egg
Custard Jelly
Over Boiled Rice with Dal,
Minced Mutton or boiled fish
Bread Or Chapatti Soaked in milk and sugar

NOTE: Sometimes its very difficult to accept new food, so at time try one type of food for several days.

General Principal:
1.     Since the child moves the tongue as though for sucking, it is but natural that some of the
semisolid given will be coming of the mouth. It is not spitting or rejection of food.
2.     Since the baby is used to the taste of milk alone, it is better accepted if the weaning food is
mixed with milk.
3.     He should encourage to feed, but should never be forced, as this creates an aversion to
feeding.
4.     Give small quantity of food, gradually increased as per demand.
5.     If he rejects any food item, it should be stopped, and may be reintroduce a week or two later.
6.     It is preferable to introduce only one new food a week, so that intolerance can be spotted.

Preparation and Storage of weaning food:
1.     Careful hygienic preparation and storage of weaning food to prevent contamination.
2.     Before preparation and weaning hand should be washed with soap.
3.     Cooking place and utensils must be clean.
4.     The food preferably fresh, cooked or boiled well and if feasible, prepared immediately before
the are to be eaten.

Thanks
"I Wish Your Baby Good Health"
Regards, Dr. Sagar Mhatre