Smooth muscle is a type of involuntary muscle that is found in the hollow internal structures of the body such as blood vessels, trachea, esophagus, stomach, intestines, colon, ureter, and bladder. Smooth muscles line the hollow structures in a circular way that when the muscle contracts, it causes the hollow structures to be squeezed and reduces the diameter. Pain due to smooth muscle spasm occurs due to the abnormality of the muscles contraction that causes the air or fluid in the hollow structures to be squeezed. Pain due to smooth muscle spasm is described as colicky pain. Colicky pain is a pain that is not continuous and occurs on and off. Examples of conditions that can lead to pain due to smooth muscle spasm are kidney stones, ureteric stones, gastroesophageal reflux disease, constipation, diarrhea, bronchial asthma, menstrual cramps, coronary artery disease, and atherosclerosis. Pain due to muscle spasm should be diagnosed and treated accordingly to avoid serious complications.