#1 Not eating enough fiber, aim at 20 grams daily unless you’re heavy than more.
#2 You’re dehydrated. Drink more around 2 liters daily of fluids.
#3 You’re taking drugs. Some drugs can give you constipation if prescribed talk with your doctor.
#4 Hooked on laxatives. Taking it once in a while is ok but relying on them makes your colon lazy.
#5 Movement. Movement help’s the intestines move your food. Go for brief walks or exercise, make it a habit.
Eat more fruit, vegetables and just drink more. Very easy solutions but if needed get laxatives that don’t make your stomach lazy.