1. Red Patches on the Butt: Sudden appearance of red patches on the butt may be a sign of rheumatic immune diseases such as lupus erythematosus or dermatomyositis.

2. Masses Around the Buttocks: Some individuals may mistake these masses for hemorrhoids and disregard them. However, if you notice the presence of masses around the buttocks or experience extreme pain, it could be an indication of tumors or nodules developing in the area.

3. Dark Stool: Also known as "melena" or "tarry stools", this condition indicates bleeding in the gastrointestinal tract. If dark stools are accompanied by symptoms such as stomach pain, fatigue, weight loss, night sweats, loss of appetite, and low-grade fever, it could be a sign of gastric or colorectal cancer.

Immediate medical attention is recommended to undergo tests such as a stool examination, gastroscopy, and colonoscopy to diagnose any gastrointestinal abnormalities.