Constipation. Although diarrhea is a common gluten allergy symptom, some sufferers experience constipation instead. Celiac disease can harm villi in the intestinal tract. Villi are projections within the small intestine that soak up minerals and nutrients. Usually, when food goes through the digestive system, the villi soak up the nutrients. These nutrients produce excess moisture in the stool. However, if the villi are scarred they can not soak up the extra moisture, resulting in constipation.
