menstrual cramps, low abdominal pain that may range from a colicky feeling to a constant dull ache. The pain may radiate to the lower back and legs. Menstrual cramps are often associated with the beginning of menses, reaching a peak in 24 hours and subsiding after 2 days. Treatment may include administration of ibuprofen or other drugs immediately before and after the start of menses. See also dysmenorrhea.