Menstrual cramping pain from anus to rectum

The twitching pain in the anus and rectum is due to perianal muscle spasm. This type of pain is mainly caused by functional disorders or anorectal diseases, which lead to spasms. It is usually not related to menstruation. Patients need to go to the hospital for relevant examinations based on the different manifestations and reactions of the body, so as to correctly judge the pathological factors.

Basic Introduction

PF often occurs suddenly and irregularly during the day or night, and the patient is awakened by pain at night. PF was first reported by Myrtle in 1883, and Thaysen formally named it "spasmodic anorectal pain" in 1935, and gave a detailed description of the characteristics of its attacks. However, there are few reports on PF in China. The prevalence of PF in the general population is 2% to 8%, and it is more common in women. Because the disease occurs infrequently and lasts for a short time, it is often not taken seriously by patients. Only 17% to 20% of PF patients will consult a doctor.

Pathogenesis

1 Anal muscle spasm It is believed that the spasm and contraction of the pelvic muscles including the levator ani muscle, puborectalis muscle, and sphincter are the cause of PF. Rao and Hatfield measured the electromyographic activity of the anal muscles of PF patients and found that the pain attacks were accompanied by high-amplitude and high-frequency abnormal electromyographic activity of the sphincter, pointing out that paroxysmal anal hyperactivity is a prominent feature of PF. Eckardt conducted a control study on 18 PF patients and 18 healthy subjects matched with gender and age, and found that when pain occurred, the resting tension of the anal canal of PF patients increased, the amplitude of slow waves increased, and sometimes intermittent smooth muscle dysfunction occurred. Therefore, he believes that the anal sphincter of PF patients will show dynamic abnormalities during an attack.

2 Colorectal dysfunction Harvey pointed out that the pain of PF patients was caused by the contraction of the sigmoid colon rather than the spasm of the levator ani muscle, rectal wall or anal sphincter by measuring the pressure in the rectum and sigmoid colon during pain attacks. At the same time, Harvey also pointed out that PF is an abnormal manifestation of irritable bowel syndrome (IBS). Pfenninger et al. also believed that PF may be related to the spasmodic contraction of the rectum or pelvic floor muscles in IBS patients.

3 Hereditary internal sphincter myopathy A rare hereditary internal sphincter myopathy is considered to be an important cause of PF and constipation. Kamm pointed out that in a family with a history of hereditary internal sphincter myopathy, at least one family member in every five generations suffers from severe PF, which often occurs at the age of 30 to 50 and is accompanied by constipation. The patient's anal resting pressure increased, intracavitary ultrasound showed hypertrophy of the internal sphincter, and histology showed vacuolar changes in smooth muscle fibers containing polysaccharide inclusions that were positive for periodic acid-Schiff staining (PAS). Kamm believed that this was a special autosomal dominant myopathy. Afterwards, many scholars have conducted relevant investigations and studies on PF caused by hereditary internal sphincter myopathy, and hypertrophic internal sphincter was found under ultrasound. However, the characteristic PAS polysaccharide inclusions were not found in the cases reported by Fernando, and he believed that vacuolar myopathy might have a histological variant form.