What are the characteristics of abdominal pain in colorectal cancer?

Colorectal cancer patients often experience abdominal pain symptoms. The incidence of abdominal pain in colorectal cancer patients is about 60%-81%, which is much higher than abdominal distension. The main causes of abdominal pain are as follows:

① Local invasion of the tumor, especially when it invades the submucosal layer or muscular layer. The frequency and severity of pain increase and become more severe as the depth of invasion increases;

②Pain caused by intestinal irritation caused by tumors;

③ When the tumor invades other adjacent organs and adheres to each other, it causes pulling pain, which can be significantly aggravated when the patient walks or moves;

④Pain caused by intestinal obstruction caused by tumors;

⑤ Abdominal pain caused by carcinomatous intestinal perforation caused by tumor.

Patients often describe the nature of colorectal cancer pain as dull pain, slow pain, and knife-like pain, or dull pain and bloating in the abdomen only after eating. Sometimes it can be similar to the symptoms of cholecystitis or duodenal ulcer, which is mainly caused by inaccurate localization of abdominal pain (referred pain). A small number of patients may also experience back pain, which is mainly related to the traction of the colon.

The pain can be divided into paroxysmal pain and continuous pain according to the duration. Paroxysmal pain often occurs when the intestinal cavity is obstructed and is caused by intestinal irritation caused by the tumor. The pain intervals are the same as those of normal people. However, when the tumor penetrates the entire layer of the intestinal wall and adheres to the surrounding tissues, the pain may intensify and turn into continuous pain (with no obvious intervals in the pain).

Sudden severe abdominal pain accompanied by abdominal tenderness and a feeling of the abdomen being like a wooden board indicates intestinal perforation, which requires urgent laparotomy. If the lesion is located in the rectum and anal canal, the incidence of abdominal pain is relatively low, the pain is felt at the bottom, is mainly persistent, and is significantly aggravated during defecation.

When the tumor invades the sacral plexus and sacrum, it can cause persistent severe pain like a knife-like pain, which is often unbearable for patients. In addition, the characteristics of abdominal pain are also related to the age of the patient. For example, the abdominal pain of middle-aged and elderly patients with colorectal cancer is mostly dull pain, while the pain of young patients is mostly severe abdominal pain. This may be related to the reduced pain sensitivity of the elderly.