Yes, it's fairly normal in some cases. The physical activity during sex can shift things around in your abdomen. Your body's autonomic nervous system, which controls involuntary functions like digestion, can also be affected during sex. This might lead to the urge to have a bowel movement. For example, if you engage in more vigorous sex, it can put more pressure on the internal organs and trigger that feeling.
It can be normal. During sexual intercourse, there is a lot of physical movement and muscular contraction. This can affect the intestines and cause the urge to defecate. Additionally, the body's physiological response to sexual arousal and orgasm can influence the digestive tract. Sometimes, the body's relaxation after sex can also make the urge more noticeable. However, if it's accompanied by pain or other abnormal symptoms, it might be a sign of an underlying issue and should be checked by a doctor.