<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been experiencing pain in my anus, constipation, nausea, incontinence of stool, and have vomited blood, what could be wrong with me?  <response>: Based on your symptoms, it seems that you might be suffering from intestinal obstruction. It occurs when there is a blockage in your intestine that prevents food and liquid from passing through the digestive tract. 