Hi. Thanks for your query. the pains in lower abdomen when trying to push to defecate indicates the following possibilities : -Inflammation of the bowel called Entero-colitis. - Pelvic Inflammatory disease or congestion , may be related to the premenstrual syndrome. Your mentioning of the details about the character of the stool, presence of blood and mucus and other factors would have helped me a lot. A 5-day course of an antibiotic and metronidazole, probiotics, anti-spasmodic may help you to get a complete relief. If no relief you will need further investigations like the tests of blood, urine, stool, ultrasonography and colonoscopy to find hte rot cause and an opinion of a Gastroenterologist and Gynecologist. I hope this answer helps you.