After a period of time a person may stop feeling the urge. This leads to progressive constipation. People who habitually take laxatives become dependent upon them and may require increasing dosages until, finally, the intestine becomes insensitive and fails to work properly. People often experience constipation when traveling long distances, which may relate to changes in lifestyle, schedule, diet, and drinking water. Certain hormonal disturbances, such as an underactive thyroid gland, can produce constipation.
Pregnancy is another common cause of constipation.
The reason may be partly mechanical, in that the pressure of the heavy womb compresses the intestine, and may be partly due to hormonal changes during pregnancy. Fissures and Hemorrhoids. Painful conditions of the anus can produce a spasm of the anal sphincter muscle, which can delay a bowel movement. Many diseases that affect the body tissues, such as scleroderma or lupus, and certain neurological or muscular diseases, such as multiple sclerosis, Parkinson's disease, and stroke, can be responsible for constipation. Loss of Body Salts.