The problem of diarrhea may be related to dysentery, ulcerative colitis, colorectal cancer and so on. 1. Dysentery: If patients eat unclean food, they may be infected with dysentery bacillus, which releases toxins and stimulates the intestinal mucosa, causing inflammation and ulceration of the intestinal mucosa, which makes patients have the symptom of having diarrhea and can’t go to the toilet. 2. Ulcerative colitis: The lesions of ulcerative colitis are mainly confined to the mucosa and submucosa of the large intestine. Inflammation stimulates the intestinal mucosa, leading to impaired absorption of water and sodium by the colonic mucosa and malfunction of colonic motility, which makes the patients suffer from the symptom of having diarrhea and not being able to go to the toilet. 3. Colorectal cancer: if the epithelial cells of the colon undergo malignant transformation, the cancer cells proliferate and invade the intestinal mucosa and submucosal blood vessels, and the absorption function of the colon is impaired, thus making the patient suffer from diarrhea. When the cancer cells invade the rectum, it can lead to rectal irritation symptoms, and the patient may have the symptom of having a tummy problem that can’t be held in the toilet all the time. There are many other reasons for having diarrhea, so it is recommended to go to the hospital in time to complete colonoscopy and routine fecal examination to clarify the cause of the disease, so as to get treatment in time.