Diverticulitis: Given the location of the pain (left lower abdomen) and the patient's age (52), diverticulitis is a common condition that fits this presentation. It involves inflammation of the diverticula in the colon, which can cause severe abdominal pain, changes in bowel habits, and fever.

Constipation: This is a common issue that can cause abdominal pain, especially in the lower quadrants. The pain can be crampy and may be accompanied by bloating and difficulty passing stools.
Irritable Bowel Syndrome (IBS): IBS can cause chronic or recurrent abdominal pain, often associated with changes in bowel habits (diarrhea or constipation), bloating, and gas.
Ovarian Cyst: Although less common in postmenopausal women, ovarian cysts can still occur and cause lower abdominal pain. The pain can be sharp or dull and may be accompanied by other symptoms like pelvic pressure.
Urinary Tract Infection (UTI): UTIs can cause lower abdominal pain, especially if the infection involves the kidneys (pyelonephritis). Symptoms may include dysuria, frequent urination, and fever.

Ectopic Pregnancy: Although the patient's last menstrual period was recent, ectopic pregnancy must be considered, especially if there's any chance of pregnancy. It's a life-threatening condition that requires immediate medical attention.
Appendicitis: While appendicitis typically presents with right lower quadrant pain, it can occasionally present atypically, especially in older adults or if the appendix is located in an unusual position.
Ruptured Ovarian Cyst: A ruptured ovarian cyst can cause severe, sudden pain and is a medical emergency.
Bowel Obstruction: This condition involves a blockage of the intestine, which can cause severe abdominal pain, vomiting, and constipation. It requires prompt medical attention.

Endometriosis: Although more common in younger women, endometriosis can still occur in postmenopausal women, especially if they are on hormone replacement therapy. It causes chronic pelvic pain, dysmenorrhea, and dyspareunia.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic abdominal pain, diarrhea, weight loss, and fatigue. They are less common but should be considered in the differential diagnosis.
Lymphoma: Abdominal lymphoma can cause pain, weight loss, and other systemic symptoms. It's a rare diagnosis but important to consider in the differential.
Gastrointestinal Stromal Tumor (GIST): GISTs are rare tumors of the digestive tract that can cause abdominal pain, bleeding, and other symptoms. They are typically found in the stomach but can occur in the small intestine.