Menudo in the Philippine context is a hearty stew of diced meat and innards in a tomato-based sauce. In Spanish menudo refers to offal, intestines, viscera. Alternate meanings include small as well as often. All those meanings could apply to the dish which incoporates small pieces of meat and offal that are often left over from the preparation of other dishes. Usually the meat consists of pork and liver and possibly sausage. Menudo has evolved in many Hispanic countries. Filipino menudo bears a closer resemblance to the Spanish stew than the Mexican soup.
Callos is another originally Spanish dish that shares close similarities and overlap but its featured ingredient is tripe for which the dish gets its name. While some versions of menudo also include tripe, in callos other meat tends to be less prominent as thinner slices of ham or bacon tend to substitute for the chunky pieces of pork and liver more commonly found in menudo. Callos is also generally more likely to include chickpeas (garbanzos) and have a thinner sauce.