Overview
A benign elevated lesion protruding from the mucosal epithelial surface of the large intestine into the intestinal lumen. Most patients have no obvious symptoms, but some may have symptoms such as blood in the stool, abdominal pain, discharge of polyps, and changes in bowel habits. The cause of the problem is unclear, and it may be related to heredity, diet, and inflammatory bowel disease.
Definition
A colorectal polyp is any bulging lesion of epithelial origin from the mucosa of the large intestine that protrudes from the surface into the lumen.
They can be single or multiple, and most of them are asymptomatic when the polyp is small. As the polyp grows, some patients may experience abdominal pain, diarrhea, blood in the stool, mucus in the stool, or a sense of urgency and heaviness.
Classification
According to Morson’s histologic classification
Neoplastic polyps: high risk of malignancy, common histologic types include tubular adenomas, choriocarcinomas, and mixed adenomas; less common types include adenomatosis.
Dysplastic polyp: a bulging lesion of the intestinal lumen with normal tissue but structural abnormalities; common types include Peutz-Jephers syndrome, juvenile polyp syndrome, and Cronkhite-Canada syndrome.
Inflammatory polyps: benign elevated lesions that appear when the mucosa is irritated by inflammation; common types include inflammatory polyps and pseudopolyposis.
Proliferative polyps: benign elevated lesions arising from mucosal hyperplasia caused by chronic inflammatory stimulation of the mucosa, common types include hyperplastic polyps, hypertrophic mucosal cumbersome organisms, and so on.
Colonoscopic Yamada typing
Yamada type I: broad-based bulge.
Yamada type II: hemispherical bulge.
Yamada type III: with subtympanic elevation.
Yamada type IV: There is obvious formation of the tibia.
Incidence
The incidence of colorectal polyps varies widely in the literature, ranging from 10% to 66% [1]. The detection rate of adenomas is on the rise in China.
Colorectal polyps are most common in the middle-aged and elderly population, accounting for about 75% of those over 60 years of age. Men outnumber women by about 2:1 [1].
Etiology
Causes
The causes and pathogenesis of colorectal polyps are unknown, and current studies suggest that they are associated with the following factors.
Genetic factors
Colorectal polyps are hereditary, and mutations in some genes (e.g., APC, MMR, etc.) can increase the risk of the disease.
Dietary factors
A high-fat, low-fiber diet, smoking and alcohol consumption can increase the risk of polyp formation.
Inflammatory stimuli
Inflammatory bowel diseases such as ulcerative colitis, Crohn’s disease, as well as chronic colitis, proctitis, constipation, etc., can stimulate intestinal mucosal epithelial hyperplasia and submucosal granulation tissue formation, resulting in polyps.
Symptoms
Main Symptoms
Colorectal polyps are mostly asymptomatic. With the growth of polyps, some patients may have blood in stool, abdominal pain, polyps discharging out of the body or prolapsing out of the anus, and changes in bowel habits.
Blood in stool
Most of the first symptoms.
Rectal polyp bleeding for the surface of the stool with blood, sigmoid colon, descending colon polyp bleeding for the stool for the dark red, the right half of the colon polyp bleeding blood often can not be seen with the naked eye.
If the blood in the stool for a long time, it may also cause anemia.
Abdominal pain and bloating
It occurs around the navel and is often sudden.
There may be abdominal discomfort, bloating, and a vague feeling of pain.
Polyps are discharged from the body or prolapse out of the anus.
Some polyps with long tips can be discharged from the feces when they twist or break, and some rectal polyps can prolapse out of the anus during defecation.
They may recover on their own or be maneuvered back in.
Change in bowel habit
Some patients have constipation or diarrhea, or alternating constipation and diarrhea.
In some patients, polyps may irritate the rectum and cause anal swelling, accompanied by a feeling of urgency and heaviness.
Some patients have excessive secretion of intestinal fluid and mucus covering the surface of the stool.
Complications
Bowel obstruction
In patients with colorectal polyps, the polyp will slowly increase in size as the disease progresses. When the diameter of the polyp is relatively large, it can cause narrowing of the intestinal lumen, and therefore may lead to intestinal obstruction.
Symptoms such as severe abdominal pain, bloating, and cessation of bowel movement may occur.
Anemia
Patients with colorectal polyps have recurrent blood in the stool, which can lead to anemia if not treated in time.
Common symptoms include pale skin, mucous membranes, nail beds and easy fatigue.
Colorectal cancer
Tumorous colorectal polyps may show malignant changes and develop into colorectal cancer.
Common symptoms include blood in the stool, bloating and abdominal pain.
Intussusception
If the polyp is large, it may cause relaxation of the intestinal mucosa, which may lead to intramucosal intussusception.
Common symptoms include paroxysmal abdominal pain and blood in stool.
Gastrointestinal bleeding
Lower gastrointestinal bleeding can occur when the polyp undergoes ulcer formation with bleeding, or when the polyp tip twists and causes rupture or breakage.
Common symptoms include blood in the stool, dizziness and fatigue.
Consultation
Department of Medicine
Gastroenterology
It is recommended to consult the Department of Gastroenterology in case of blood in the stool, abdominal pain, diarrhea or constipation, or if colonoscopy reveals colorectal polyps.
Preparation
Consultation: Registration, Preparation of documents, Frequently Asked Questions
Tips for seeking medical treatment
If you have blood in the stool, it is recommended that you seek medical attention as soon as possible.
Preparation Checklist
Symptom list
Pay particular attention to the time of onset of symptoms, special manifestations, etc.
Is there an increase or decrease in the frequency of stools? What color is the stool?
Is there any bloating or abdominal pain?
How long have these symptoms been present?
Under what circumstances can these symptoms be aggravated or relieved?
Medical History Checklist
Have parents, siblings, etc. suffered from colorectal polyps, bowel cancer, etc.?
Any ulcerative colitis, Crohn’s disease, chronic colitis, constipation, etc.?
Has there been a previous colonoscopy with detection of colorectal polyps?
Checklist
Test results in the last six months, which can be brought to the doctor’s office
Laboratory tests: fecal occult blood test, routine blood test, blood carcinoembryonic antigen (CEA).
Imaging tests: abdominal ultrasound or abdominal CT, abdominal x-ray, barium x-ray
Endoscopy: colonoscopy.
Diagnosis
Diagnosis is based on
Medical history
Family history of colorectal polyps, intestinal cancer.
History of ulcerative colitis, Crohn’s disease, chronic colorectitis, constipation.
Clinical manifestations
Symptoms
Abdominal pain, abdominal distension, blood in the stool, change in bowel habit, and discharge or prolapse of polyps out of the anus.
Laboratory tests
Fecal Occult Blood Test
The fecal occult blood test is to see if there is blood in the stool to determine if the patient has gastrointestinal bleeding.
If the test result is positive, the stool may contain blood due to colorectal polyps.
Routine blood tests
A routine blood test is performed to determine if the patient has anemia.
A lowered hemoglobin may indicate anemia.
Blood Carcinoembryonic Antigen Test
Some patients with colorectal polyps have elevated blood tests for CEA, especially if the polyp is cancerous.
Imaging
Abdominal X-ray
To see if the patient has an intestinal obstruction.
The presence of enlarged intestinal collaterals and a flat air-fluid pattern suggests that a colorectal polyp may be blocking the intestinal tract and causing intestinal obstruction.
Abdominal CT examination
Abdominal CT examination can detect the location of some large colorectal polyps.
Barium X-ray
Barium X-ray can be used for patients who cannot tolerate colonoscopy, but it may miss smaller polyps.
Colonoscopy
Colonoscopy can directly check the condition of the patient’s intestinal lumen, clarify whether there are large intestinal polyps, and at the same time can observe the shape, number and size of the polyps.
Precautions: Three days before the examination, you need to have a diet with little or no residue (e.g. porridge, milk, noodles and other foods with less crude fiber content), and you need to clean the intestines before the examination, and you may experience abdominal distension, abdominal pain and other uncomfortable symptoms during the examination.
Histopathologic examination
Partial tissue clamping or endoscopic resection of the polyp is performed and sent to the pathology department for histologic examination.
Differential Diagnosis
Colorectal cancer
Similarities: Both colorectal cancer and colorectal polyps have symptoms such as abdominal pain, bloating, blood in the stool, and changes in stool texture.
Differences:
The mass of colorectal cancer is often large in size, with uneven surface, ulcer formation or cauliflower pattern, which may be accompanied by bleeding and dirty moss on the surface, and can be diagnosed through pathological tissue biopsy.
Colorectal polyps have a smooth surface and are clearly diagnosed as benign by histopathologic biopsy.
Familial adenomatous polyp
Similarities: both have a bulging mass in the lumen of the bowel.
Differences:
Familial adenomatous polyps can number from tens to hundreds and can be found in the colon, rectum, stomach, and duodenum.
Colorectal polyps are single or multiple and are found in the colon and rectum.
Treatment
Aim of treatment: to relieve symptoms and reduce complications.
Treatment principle: Adenomatous polyps should be removed endoscopically as far as possible; inflammatory polyps only need regular review; hyperplastic polyps generally do not cause symptoms and do not require special treatment.
Endoscopic treatment
After accurately locating the position of the polyp through colonoscopy, biopsy forceps, endoscopic mucosal resection, endoscopic submucosal dissection and other methods are used to treat colorectal polyps, which is the preferred method of colorectal polyp treatment due to its low trauma and the ability to operate on multiple lesions at the same time.
Surgical complications include bleeding, perforation and infection.
Thermal biopsy forceps removal
Indications: generally applicable to small polyps of 1 to 5 mm.
Methods: Insert an electrically charged thermal biopsy forceps through the colonoscope, open the two mouths of the forceps and then clamp the polyp, energize it, and then use the heat generated by the electrical energy to cut down the polyp.
Argon ion coagulation (APC)
Indications: For patients with small or flat polyps.
Methods: Argon ionization, high-frequency energy transmission to the surface layer of polyps, argon plasma without contact can produce coagulation effect on the target tissue, thus playing a hemostatic and polyp excision of the therapeutic effect.
High-frequency electrocoagulation and electrocision
Indications: Widely used for all sizes of pedunculated polyps and non-pedunculated polyps with a diameter of less than 2cm, as well as a small number of scattered polyps.
Methods: Insert an electrically charged loopers or thermal biopsy forceps through the colonoscope, energize it, and then use the heat generated by the electrical energy to cut down the polyps.
Endoscopic mucosal resection (EMR)
Indications: For non-tipped, flat polyps.
Methods: Using a hypodermic needle to inject fluid (methylene blue, etc.) into the submucosal layer, the polyp is lifted up, and then the polyp is removed by complete circling with a circling device.
Endoscopic submucosal dissection (ESD)
Indications: For patients with large, broad-based, laterally developed polyps or early cancerous colorectal polyps.
Methods: Methylene blue is injected into the submucosal layer underneath the lesion to elevate the lesion, and then an IT knife or flex knife is used to gradually cut around and at the base of the lesion, and finally the lesion is completely removed.
Laser treatment
Indications: For colorectal polyps.
Methods: When the laser acts on the polyp, it produces thermal effect causing protein denaturation, tissue necrosis and carbonization, burning until gasification, so as to achieve the purpose of removing the polyp. It is rarely used at present.
Surgery
Colon resection
It is indicated for patients with multiple colorectal polyps that cannot be removed by colonoscopy and for patients with cancerous colorectal polyps.
It is usually performed as a partial or radical resection to improve the prognosis and survival rate of the patient.
Laparoscopic surgery
Laparoscopic surgery is indicated for patients with colorectal polyps that cannot be completely removed by colonoscopy but do not require open surgical treatment.
Advantages include less trauma and faster postoperative recovery.
Prognosis
Cure
The prognosis of colorectal polyps is generally good through timely treatment, but recurrence in other parts of the body may occur.
Tumorous colorectal polyps are at risk of becoming cancerous and prompt detection and treatment is recommended.
Routine
Daily management
Dietary management
Pay attention to dietary hygiene.
Eat more vegetables and fruits, such as carrots, celery, broccoli, bananas, etc., to get enough dietary fiber and vitamins, which will help intestinal health and avoid constipation.
Supplement more protein-rich foods, such as lean meat, fish, eggs and milk, to enhance nutrition.
Eat less high-fat and stimulating food in daily life.
Daily life management
Ensure sufficient sleep and do not stay up late.
It is recommended to strengthen outdoor physical exercise, such as brisk walking, skipping, swimming, etc., to maintain good health and enhance body resistance.
Quit smoking and drinking.
Psychological management
Patients with colorectal polyps may suffer from anxiety, depression and other adverse emotions. It is necessary to strengthen communication with patients and encourage them to maintain an optimistic mindset.
Follow-up review
The timing of the review is usually decided based on colonoscopic pathologic findings, completeness of resection, bowel preparation, health status, family history of polyps and past medical history.
After treatment of adenomatous polyps, colonoscopy is usually repeated six months to one year later. If there are no new adenomatous polyps, the frequency of follow-up colonoscopy can be extended to once every two years.
The main review is a colonoscopy.
Prevention
Aggressive treatment of chronic colitis, ulcerative colitis, Crohn’s disease and other diseases can prevent the development of colorectal polyps.
Try not to smoke or drink alcohol.
In daily life, we should have a balanced diet, eat less spicy and stimulating, high-fat food, and eat more fruits and vegetables.
Take appropriate calcium supplement combined with vitamin D.
Maintain good bowel habits to avoid constipation.
Exercise actively, control weight and improve immunity.
Follow the doctor’s instructions for regular review in order to find out whether there is recurrence in time.
It is recommended that healthy people over 45 years of age begin regular colonoscopy.
As colorectal polyps have a certain hereditary tendency, patients with pathology suggesting adenomatous polyps are advised to have their family members undergo colonoscopy to rule out the possibility of colorectal polyps and colorectal cancer.