What are the symptoms of rectal cancer?

Rectal cancer may be asymptomatic in the early stages, but as the cancer gradually grows, a series of symptoms may occur.

1. Blood in the stool is the most common symptom of rectal cancer, but it is often ignored by patients. Blood in the stool is mostly red or dark red, mixed with fecal mucus, blood or pus, and sometimes accompanied by blood clots and necrotic tissue. The above symptoms are caused by blood flow obstruction caused by tumor proliferation, tissue necrosis, erosion, ulceration and infection, and ulceration.

2. Changes in bowel habits. The mass and its secretions can cause intestinal irritation symptoms, such as frequent bowel movements, a feeling of incomplete defecation, and tenesmus. However, the discharge is mostly mucus, pus, and blood. Initially, these "false diarrhea" phenomena often occur shortly after getting up in the morning, which is called morning diarrhea. Later, the frequency gradually increases, and the patient may even be unable to fall asleep at night, which changes the previous bowel habits.

3. Intestinal stenosis and obstruction. Cancer infiltrates around the intestinal wall, narrowing the intestinal cavity, especially at the junction of the rectum and sigmoid colon. Most of them are stenotic sclerosing cancers, which are very likely to cause obstruction. The stool becomes thinner, defecation is difficult, constipation occurs, and abdominal discomfort, bloating and pain occur.

4. Anal pain and anal incontinence. If the lower rectal cancer infiltrates the anal canal, it can cause local pain. If it involves the anal sphincter, it can cause anal incontinence, with pus and blood often flowing out and contaminating underwear. Cancer infection or metastasis can cause enlargement of the inguinal lymph nodes.

5. Other late-stage rectal cancers that infiltrate other organs and tissues can cause symptoms of these lesions. For example, if the sacral plexus is invaded, it can cause pain in the sacral region and perineum, similar to pain in the sciatic nerve. If the bladder and prostate are invaded, it can cause cystitis, urethritis, vesicorectal fistula, urethral rectal fistula, and vaginal rectal fistula in women, with feces and mucus, pus and blood discharged from the vagina.