Hello! Thank you for the query. Such embarrassing thing can be life threatening so doctors visit might be necessary. You may suffer from constipation or bowels obstruction. And you are unable to tell which one has caused your problems as long as you wont make an X-ray of your abdomen. Constipation can be caused by bad diet (low fiber intake, low mineral water intake), thyroid disease, medicines (antidepressants, Ca-blockers), chronic bacterial infection. Bowels obstruction can be caused by large intestine cancer or inflammatory bowels disease. With an obstruction you may have also gas blockage (with constipation gas goes freely), abdominal pain and blood in stool. I suggest you to visit your doctor and have it diagnosed. Abdominal X-ray, blood work, abdominal ultrasound should be done at first. Colonoscopy should be also scheduled. Hope this will help. Regards.