Tests for Constipation Constipation is a very common symptom and can be caused by many things. Sometimes many tests may be needed to clarify the cause of constipation. First, it is necessary to do an understanding of the patient’s general health condition, such as the presence of high hypertension, coronary heart disease, diabetes, hypothyroidism, and some neurogenic diseases (such as cerebrovascular accident, Parkinson’s disease, multiple sclerosis, depression, anorexia nervosa, etc.), and the presence of poor living and eating habits and special medications. Second, to do a detailed examination of the rectal bowel movements, these tests are probably the following categories. 1, rectal finger examination patients generally take the left side of the lying position, supine position or elbow and knee position, the doctor wear gloves and coated with paraffin oil and other lubricants, gently massage around the anus, fingers slowly inserted into the anus and rectum for touch examination. Rectal finger examination helps to understand whether the patient has rectal tumor, inflammation, prolapse, stricture, fecal mass, hemorrhoid, anal fissure, anal sphincter spasm or relaxation, and to determine whether there is outlet obstructive constipation. Rectal finger examination is one of the important tests for initial screening of constipation. 2.X-ray examination (barium meal examination) This is a method to carefully observe the lesions of the digestive tract by inflating the digestive tract and swallowing barium that can be visualized under X-ray after photography. On the one hand, barium meal examination can find out whether the patient has organic lesions, and at the same time, it can also be used to understand the time of barium passing through the gastrointestinal tract and the functional status of small intestine and colon. Under normal conditions, barium can reach the splenic flexure of the colon within 12 to 18 hours, and all of it should be expelled from the colon within 24 to 72 hours, and emptying is often delayed in cases of constipation. People with irritable bowel syndrome often show deepening of the colonic pouch, colonic spasm, and sometimes thread-like signs. For patients with complete intestinal obstruction, barium meal examination should be contraindicated. In order to clarify the nature, location and extent of organic lesions of the colon, barium enema is appropriate. High-quality air-barium double contrast imaging can even detect microscopic cancer foci of 0.5 cm in diameter. However, the disadvantage of this kind of examination is that the tissue cannot be taken for pathological examination. 3.Colonoscopy During colonoscopy, a several-meter-long, finger-thick mirror is inserted from the anus to the vicinity of the cecum, so that the doctor can directly observe the situation inside the intestine of the patient, such as whether the mucosa is congested and edematous, whether there is a mass blockage in the intestinal cavity, whether there are ulcers or polyps in the intestine, and so on. This test is necessary when a patient with constipation has abdominal pain, blood in the stool, thinning of the stool shape or simultaneous weight loss. However, if intestinal perforation, acute bleeding in the intestine or inflammation is suspected, the intestine is easily damaged by colonoscopy and is not suitable for colonoscopy: in addition, elderly patients, patients with coronary heart disease and hypertension, patients with poor lung function, patients with a history of stroke, etc. must be cautious when doing this test. The biggest advantage of this examination is that pathological biopsy and some basic treatment (taking polyps) can be done. 4.Fecal imaging is to simulate feces by instilling barium into the rectum and dynamically observe the functional changes of the anus and rectum during the process of barium discharge (simulated defecation) under radiation. The purpose of the fecal imaging is diagnostic and differential diagnosis to distinguish whether constipation is functional or due to organic diseases of the anus, rectum and pelvic floor. The results of this test are easily affected by the patient’s emotion, environment, tension and other factors, therefore, the diagnosis of defecation disorder cannot be made based on the results of the fecal imaging alone, but requires a comprehensive analysis by experienced clinicians based on symptoms, medical history and other test results to make a correct judgment. 5, colonic transmission test colonic transmission test, also known as gastrointestinal transmission test, is to let patients swallow the markers visible under x-ray, and then every certain time through x-ray on the patient’s abdomen, in order to understand the operation of these markers in the intestinal tract and the obstruction of the place, so as to make a diagnosis of the cause of constipation a method, this method is basically painless, but more time-consuming. A test meal containing 20 markers is usually swallowed at breakfast, and abdominal films are taken at regular intervals to see how fast the markers are moving through the intestine and how they are distributed, so that the rate of elimination can be calculated. Normally, 48-72 hours after swallowing the test meal, most of the markers have been excreted. Based on the distribution of markers on the abdominal plain film, it is useful to assess whether the constipation is of the slow-transmission or outlet obstruction type. Due to the influence of diet and other factors, different results can be obtained in the same patient at different times, so it is necessary to review after a period of time for those patients who require surgical treatment due to the poor results of non-surgical treatment. 6.Anal rectal pressure measurement Anal rectal pressure measurement refers to putting a special pressure measurement device inside the anus to understand whether the muscles and organs related to defecation function normally or not, and whether different organs can work in a coordinated manner by detecting the pressure in the rectal canal. For example, whether the internal and external anal sphincter and the rectal canal muscles work together to pass stool out of the body. At the same time, this examination can also understand whether the function of some neural reflexes related to defecation is normal, such as the rectal-anal inhibition reflex. 7.Anal electromyography examination Anal electromyography examination refers to the application of electrophysiological techniques to detect the function of some muscles related to defecation in the pelvic cavity, including the puborectal muscles, external sphincter muscles and so on. Anal electromyography is to place electrodes on the patient’s body to detect the electrophysiological activity of the muscles related to defecation, somewhat similar to our usual ECG, without much pain, and can easily help us find the cause of constipation. 8, balloon discharge test This is a simple and practical screening method for defecation function. The specific method is to insert a catheter with a balloon at the top into the rectal jug abdomen through the anus, and then fill the balloon with different volumes of warm water or gas and ask the patient to expel it. In normal people, a balloon with a volume of 50 ml can be easily expelled within 5 minutes, while in constipated patients, because of the reduced sensory sensitivity of the rectum, only larger balloons can be expelled, especially in the case of outlet obstruction constipation, and only when the balloon is filled to more than 200 ml does the patient’s rectum produce a sensation of irritation and expel the balloon from the body. This method is mainly used to evaluate the patient’s bowel motility and rectal sensitivity. In addition, the balloon expulsion test can be used as part of a training program to restore pelvic floor function.