The pelvic floor muscles span the bottom of the pelvis and support the pelvic organs (bladder and bowel, and uterus (womb) in women).When the pelvic floor muscles contract, they help  control poop and gas . When they relax, they can allow smooth bowel movement. A pelvic floor dysfunction can create problems with bowel control. 

Both contraction and relaxation as well as coordination of these muscles is necessary for the fine control of defecation. When these muscles are too weak (after childbirth, injuries, surgeries etc), they can cause fecal leakage and poor control of flatulence. When these muscles are too tight, they can cause constipation and pain with bowel movement. They can predispose a person to developing fissures and hemorrhoids. 

Common Bowel related symptoms I treat in my practice:

1. Constipation
2. Fecal smearing 
3. Flatus leaking
4. Pain with bowel movement
5. Tailbone/rectal pain