Prolonged failure to form stools may be caused by dietary factors, indigestion, intestinal flora imbalance, ulcerative colitis and so on. 1. Dietary factors: it may be due to eating too many vegetables and fruits, and consuming more dietary fiber, which can easily lead to unshaped stools, but there are no other uncomfortable symptoms. 2. Indigestion: If there is chronic indigestion, the food intake can not be digested and absorbed in time, and the food residue will be discharged out of the body, which will lead to unshaped stools. 3. Intestinal flora imbalance: the decrease of beneficial bacteria and the increase of harmful bacteria in the intestinal tract will easily lead to intestinal dysfunction and accelerated intestinal peristalsis, which often results in more frequent bowel movements and unformed stools. 4. Ulcerative colitis: mainly due to the intestinal mucosa stimulated by inflammation, congestion, erosion and other phenomena, the stool is not shaped at the same time will lead to abdominal pain, diarrhea and other symptoms. Long-term unshaped stools may also be caused by other reasons, you should go to the hospital in a timely manner to identify the cause of the targeted treatment as prescribed by the doctor.