What causes bowel movement difficulty?

The reason for difficulty in defecating is due to too little cellulose intake, insufficient water or eating a lot of fatty foods, resulting in increased food residues in the intestine, increased fecal mass, and failure to stimulate normal intestinal peristalsis. Or due to decreased muscle tension or slow peristalsis in the intestine, fecal path obstruction, resulting in retention of intestinal contents and inability to discharge, such as intestinal obstruction, defecation nerve and muscle movement disorders, defecation reflex weakening, anal sphincter spasm disappearance, abdominal muscle disappearance and diaphragm contraction weakening.