Crabs do not directly cause blood in the stool. There are several main causes of blood in the stool, such as internal hemorrhoids, intestinal polyps, ulcerative colorectitis, and intestinal tumors. Normally, blood in the stool occurs after the disease itself has progressed to a certain point. However, crab does not have a similar effect that can cause direct blood in the stool. Therefore, there is no problem with normal consumption of crab. However, crab is a cold food. If the patient’s own spleen and stomach function is poor, overeating crab can lead to diarrhea. The increased number of bowel movements caused by diarrhea and the continuous pressure on the anus from prolonged squatting will lead to the appearance of blood in the stool or frequent blood in the stool. Although crab does not directly cause blood in the stool, it is important to take care when consuming it and control the total amount. The actual fact is that you will be able to get a good deal on your own, so as not to trigger unnecessary symptoms. Usually, eat more light, coarse fiber food.