What are rare causes of poor appetite in. A 22 year old? Colon. Or stomach cancer a realistic sign. Help me understand uncommon causes of poor appetite

Several. Numerous causes for loss of appetite several diseases , several medications from cold to cancer , some one 22 yr old with no other symptoms , only thing that causes is anxiety and depression, most common in young.You are only 22 don't think of cancers , enjoy your life.
Repeat question. There is almost no likelihood that your poor appetite is due to colon cancer. Colon or stomach cancer are illnesses not signs. Your signs are of those of a person frightened that they have an incurable disease. That's called nosophobia. It is best treated by a psychiatrist. First be screened by your family doctor (i assume she knows you well). You don"t need to live this way.