Constipation: This is a common issue postpartum, especially if the patient had a cesarean section or was immobile for a period. Constipation can cause significant abdominal pain, particularly if there is a large bowel movement or fecal impaction.

Urinary Tract Infection (UTI): Postpartum women are at increased risk for UTIs due to potential trauma to the urethra during delivery, catheter use, or postpartum urinary retention. Symptoms can include abdominal pain, dysuria, and frequent urination.
Postpartum Endometritis: Although more commonly associated with fever and uterine tenderness, endometritis can cause lower abdominal pain. It's a consideration, especially if there were complications during delivery or a history of retained products of conception.
Ovarian Cyst or Torsion: Ovarian cysts can rupture or torsion can occur, leading to acute abdominal pain. These conditions are possible in the postpartum period and require prompt evaluation.

Ectopic Pregnancy: Although the patient is recently postpartum, it's crucial not to miss an ectopic pregnancy, especially if there was a recent episode of amenorrhea followed by vaginal bleeding and now abdominal pain. The risk, although low, necessitates consideration due to its high mortality if missed.
Appendicitis: Appendicitis can present with abdominal pain that initially might be diffuse or around the navel and then localizes to the right lower quadrant, but atypical presentations, including left-sided pain, can occur. It's a surgical emergency.
Pulmonary Embolism: Postpartum women are at increased risk for venous thromboembolism, including pulmonary embolism. While the primary symptom is dyspnea, chest pain, or cough, abdominal pain can occasionally be a presenting symptom, especially if the embolism affects the lung's lower lobes.

Adrenal Hemorrhage: This is a rare condition but can cause acute abdominal pain. It might be considered in the context of severe postpartum hemorrhage or coagulopathy.
Splenic Infarction or Rupture: These conditions are rare but can cause left upper quadrant abdominal pain. They might be associated with trauma, severe hypertension, or coagulopathies.
Inflammatory Bowel Disease (IBD) Flare: While not exclusively postpartum, IBD can cause abdominal pain and might be considered if there's a history of Crohn's disease or ulcerative colitis, especially with other symptoms like diarrhea or weight loss.