Bacterial Vaginosis: This is often the most common cause of abnormal vaginal discharge, characterized by a fishy odor and a thin, watery consistency. It's caused by an imbalance of the normal bacterial flora in the vagina.

Yeast Infection (Candidiasis): Although typically associated with a thick, cottage cheese-like discharge, some cases can present with a watery discharge. It's caused by an overgrowth of Candida species.
Trichomoniasis: A sexually transmitted infection that can cause a frothy, watery, and foul-smelling vaginal discharge.
Atrophic Vaginitis: Common in postmenopausal women, it can cause a thin, watery discharge due to the thinning and drying of the vaginal walls.

Pelvic Inflammatory Disease (PID): Although PID typically presents with pelvic pain and other symptoms, a watery discharge can be a part of the clinical picture. It's crucial to diagnose and treat PID promptly to prevent long-term complications like infertility.
Cervical Cancer: While rare, cervical cancer can cause abnormal vaginal discharge, including a watery type. Regular screening is key to early detection.
Gonorrhea and Chlamydia: These sexually transmitted infections can cause abnormal discharge and have significant health implications if not treated.

Vaginal Cancer: A rare type of cancer that can cause abnormal vaginal discharge among other symptoms.
Foreign Body in the Vagina: Objects left in the vagina can cause an inflammatory reaction leading to a watery discharge.
Desquamative Inflammatory Vaginitis (DIV): A rare condition characterized by a purulent, watery discharge and significant vaginal inflammation.