Lower abdominal pain
with blood in stool
occur in many different conditions like bacterial/ viral enterocolitis
, food poisoning, Diverticulitis
, Ulcerative colitis/ crohn's disease, Amebiasis, colon cancer. All these conditions may lead to serious complications so you should consult a surgeon for proper guidance. some test should be done to arrive at a diagnosis like Stool test, CT scan abdomen, colonoscopy. Treatment depends on the test result which will be obtained.
Take care, bye.