A modality is the way or mode in which something exists or is done. You might often see it used with reference to diagnostic modality, which is the way in which a disease or illness is diagnosed by a doctor. Modality shares its root with the word mode, meaning the way in which something happens or is experienced.. A sensory modality is a way of sensing, like vision or hearing. Modality in someone's voice gives a sense of the person's mood.
Some of the causes of slow bowel movements, whether clearly defined as constipation or not, includes 1  : Dehydration. 2  Depression. 3  Eating disorders.  Hypothyroidism â underactivity of the thyroid 1  gland. Hemorrhoids.  Inflammatory bowel disease (IBD) â active phases always present with diarrhea.
Causes include: Habits, like sedentary life style, irregular meals, low-fiber diet, postponing bowel movement, overuse of laxatives resulting in a lazy colon that does not react to stimuli, like eating and presence of the stool in the rectum.