Lower abdo pain right side. Regular bowel but hard&dark. Blood I suspect rectal. Rectal pain.2day sharp pain low abdo when passing stoel. Possible cause?

Abdominal pain. I am an ER physician so right sided lower abdominal pain always concerns me. However when you have the pain when passing stool my likely thought would be rectal fissure which is helped with increased fluids and fiber. Other thought would be diverticulits or diverticular pain. If symptoms persist or worsen get checked.