hi, this may be because of your diet, not
eating meat wont cause any bad to your health, especially constipation is a condition which occurs many other reasons. One major reason is, if you are not taking fiber food regularly then this will occur, so take some fiber rich foods like whole grains. and if you still have this problem after having fiber foods then it may be because of the parasite in your stomach, so consult your doctor and go for some parasite cleanser.