A process in which force is generated within smooth muscle tissue, resulting in a change in muscle geometry. This process occurs in the distal stomach. Force generation involves a chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis. The distal stomach is composed of the lower body and antrum and develops strong peristaltic phasic contractions that increase in amplitude as they propagate toward the pylorus.