Can anal closure prevent insects from entering?

Under normal circumstances, the closure of the anus effectively prevents parasites from entering the body, but parasites may also enter through other pathways. If concerns arise, it is recommended to seek medical consultation in advance. Detailed explanation is as follows:

Under normal conditions, the anal closure prevents the reflux of intestinal contents and effectively isolates potentially harmful substances within the intestine, including parasites. When the anus is tightly closed, it prevents the exchange of materials between the inside and outside of the intestine, thus blocking the entry of parasites and other foreign objects. Therefore, when anal function is normal and the anus remains closed, parasites cannot enter.

Some parasites, such as pinworms, can lay eggs inside the human body. The eggs are excreted with feces and then hatch into larvae around the anus, subsequently re-entering the body through the anus. Additionally, poor personal hygiene habits, insufficiently washed or improperly cooked food, and unhygienic living environments may lead to parasite eggs or larvae attaching to food or hands, entering the digestive tract through the mouth, eventually reaching the intestines, and developing into adult worms.

In daily life, it is important to regularly clean the anal area, especially after bowel movements, to reduce the residue of pathogens and foreign substances. If symptoms such as anal itching, pain, or swelling occur, timely medical examination is necessary to rule out potential infections or diseases.