When you are 33 weeks pregnant, loose bowel movements most probably means that you are having diarrhea. You will, most probably have this condition towards the end of your pregnancy. Sometimes, it could just mean that you are drinking a lot of water in your pregnancy, which is a non issue. However, when you are having a lot of loose stool, you could have changed from one brand of prenatal vitamins to the other, which also causes reactions like this. Diarrhea can be very dangerous as it can cause a lot of dehydration, which is related to low blood pressure in pregnancy. Again when you are severely dehydrated at this stage of your pregnancy, the body can go into a condition that may feel like preterm labor. If this is the case, you will have to get treated as soon as possible with IV fluids to replace the water in your body. Naturally, you will have to drink a lot of water to replace the amount that has been lost. Stay away from caffeine that is present in chocolates or coffee and some medications, because it tends to reduce the amount of water in your body as well. Some foods are known to increase your chances of getting diarrhea and you should know what causes you to have diarrhea so you should stay away from them. Consume foods that have a lot of vitamins and fiber to improve your health. The cramps that come with false labor and true labor can also cause you to have some diarrhea, even if you have never had this condition in your pregnancy. This is normal, and usually it will stop as soon as your labor pains stop. You should have felt some Braxton hicks contractions by now and noticed that you have loose bowel movements when you have any of these movements.