How does Typhoid fever affect the intestines?

Typhoid fever, caused by the bacterium Salmonella enterica serotype Typhi, primarily affects the intestines through the inflammation of Peyer's patches, which are small masses of lymphatic tissue found in the ileum of the small intestine. These patches play a significant role in the immune response by monitoring intestinal bacteria and preventing the growth of pathogenic bacteria.

In the context of Typhoid fever, the bacteria invade the intestinal wall and specifically target Peyer's patches, leading to inflammation and ulceration. This inflammation can disrupt normal intestinal function and contribute to the symptoms experienced during the illness, such as abdominal pain and altered bowel function. The immune response triggered by this infection can further exacerbate inflammation in the digestive tract.

While other options mention effects like constipation, diarrhea, or increased motility, the specific and direct impact of Typhoid fever on Peyer's patches through inflammation is a critical aspect of the disease's pathology and provides insight into how the body responds to the infection. Thus, the inflammation of Peyer's patches is the key mechanism by which Typhoid affects the intestines.