The causes of irregular stools without diarrhea include indigestion, colon polyps, intestinal tumors, and chronic colitis. 1. Dyspepsia: this is usually a recent symptom, related to the patient eating too much greasy and fried food, resulting in the gastrointestinal tract to reduce the ability to digest and absorb. 2. Intestinal tumors: This condition can cause changes in the color and shape of the stool, and also cause blood in the stool, which needs to undergo colonoscopy to confirm the diagnosis. 3. Chronic colitis: this can lead to long-term inflammatory stimulation of the intestinal tract, resulting in the production of a large amount of water in the intestinal tract, resulting in unshaped stools. There are many other reasons why you may not have diarrhea, so it is recommended that you actively consult a doctor to find out the cause and receive treatment to avoid affecting your health.