There are various causes for left lower abdominal
pain.
Pain and discomfort on the lower
left side of abdomen can be due to several causes such as Crohn’s disease, diverticulitis, infection in kidney, kidney stones, adhesions, polycystic ovary in females, IBS, constipation, and an abscess in rectus abdominis muscle or psoas muscle. Since you do not have a lump or a tender hot spot, in all probability it is not a muscle.