Rectal cancer is one of the more common nauseous tumors in our daily life. Most patients with rectal cancer will have symptoms such as change in stool habit, increase in stool frequency, thin stool, etc. However, due to the low location of rectal cancer, it is often easy to differ from other diseases in terms of symptoms and diagnosis. What are the symptoms of rectal cancer and what are the diseases we need to differentiate from? The symptoms of rectal cancer are mainly the following five kinds 1. Blood in stool: it is the most common symptom of rectal cancer, but it is often ignored by patients or misdiagnosed as hemorrhoids and delayed treatment, which aggravates the condition. Blood in stool is mostly red or dark red, mixed with mucus and blood of stool or pus and blood, sometimes accompanied by blood clots and necrotic tissue. The above symptoms are caused by the obstruction of blood flow after the proliferation of cancer, necrosis and erosion of tissues, ulceration and infection, and the formation of ulcers. 2.Changes in ambassadorial habits: Due to the mass and the secretions it produces, it can produce symptoms of intestinal irritation, frequent bowel movements, the feeling of not having daytime bowel movements, and the symptoms of urgency and heaviness, but the discharge is mostly mucus-purulent and blood-like material, and initially these “pseudo-diarrhea” phenomena mostly occur in the early morning shortly after waking up, which is called morning diarrhea. diarrhea). Later, the number gradually increases, and even at night can not sleep, changing the usual stool habits. 3.Intestinal stenosis and obstruction: the cancer infiltrates around the circumference of the intestinal wall, narrowing the intestinal cavity, especially at the junction of rectum and sigmoid colon, which is mostly a stenosing type of hard cancer and is very likely to cause obstruction. Recto-pot belly cancer, because it is mostly ulcerated type, recto-pot belly is wider, it is estimated that about 1 to 2 years before it causes narrow obstruction, thin stool formation, defecation difficulty, constipation, abdominal discomfort, gas and pain. Due to the accumulation of feces, in the upper part of the obstructed sigmoid colon area, sometimes in the left lower abdomen, a striated mass can be found. 4.Anal pain and anal incontinence: If the lower rectal cancer infiltrates the anal canal, it can cause local pain, and if the anal sphincter is involved, it can cause anal incontinence, and pus and blood will often flow out and pollute the underwear; cancer infection or metastasis can cause lymph node enlargement in the groin. Invasion of sacral plexus can cause pain in sacral and perineal area, similar to sciatic nerve pain; invasion of bladder and prostate can cause cystitis, urethritis, vesico-rectal fistula and urethro-rectal fistula in women, and vaginal rectal fistula with fecal matter and mucus pus and blood discharged from vagina. Liver metastasis may cause hepatomegaly, jaundice, ascites and other symptoms, and systemic symptoms may include anemia and other cachexia, and sometimes acute intestinal obstruction, lower gastrointestinal hemorrhage and diffuse peritonitis after perforation. The symptoms of rectal cancer are very complex and diverse, and the accompanying symptoms of frequent urination, urinary urgency and painful urination will become more and more serious, and the painful areas will spread, so in daily life, we must pay attention to the changes of the body, and if there are such symptoms, we should strive for early detection and treatment. Rectal cancer is easily confused with these diseases 1. Differential diagnosis with hemorrhoids: the clinical manifestation of hemorrhoids is anal bleeding, bright red blood, small amount of blood, stool itself without blood. The bleeding is generally intermittent and occurs only after dry stools or spicy food, without abdominal pain or bloating. There is no change in the shape of stool. On the contrary, the clinical appearance of colorectal cancer is blood in the stool, which is bright red or dark red and accompanied by abdominal pain and abdominal distension, etc. The stool may be deformed. The lump can be palpated during colorectal finger diagnosis, and the finger stains with blood. 2.Differential diagnosis with colorectal polyps: colorectal polyps can also appear with blood in the stool, but they do not cause abdominal pain, abdominal distension and systemic symptoms. Colorectal finger palpation can touch soft masses, and the finger stains blood. In contrast, colorectal cancer can cause intestinal obstruction symptoms and systemic symptoms such as weakness and weight loss, and hard masses can be palpated on colorectal finger diagnosis, and the finger stains blood. 3.Differential diagnosis of anal fissure: Anal fissure is characterized by anal bleeding, which is bright red in color and not much in amount, and is characterized by severe anal pain during and after defecation. Visual examination of the anus reveals skin fissures and anterior sentinel hemorrhoids. Finger palpation can sometimes palpate hypertrophic anal papillae, and usually the finger sleeve is not stained with blood.