Is my brother, whose heart stopped after his kidneys, liver, and digestive system failed, considered among those who died "mabṭūn" (of an internal disease)?

Martyrs are five: the one who dies by plague, the one who dies by a stomach ailment, the one who drowns, the one who dies under a collapsed structure, and the one martyred in the way of Allah. The meaning of "one who dies by a stomach ailment" generally includes anyone who dies from an internal abdominal disease, such as diarrhea or dropsy, or one who dies from liver cirrhosis or appendicitis. All of these are hoped to attain martyrdom.