Thanks for the query to H.C.M. Forum.
As blood also present with green color mucus type substance.
May be due to bile acid malabsorption
( treated with cholestyramine
Other causes are ulcerative colitis
, hemorrhoids .
May be cancer in colon.
Get in ultrasound of whole abdomen with emphasis over gallbladder
and liver along large intestine.
Physical examination of abdomen as well hemorrhoid will find out the disease.
Consult a physician/ surgeon and get their opinion.