Your symptoms may be related to overactivity/tightness and poor coordination of the pelvic floor muscles, especially after repeated anal surgeries and long-standing pain. Habitually hovering or half-squatting while urinating may contribute to difficulty relaxing the pelvic floor, but it is unlikely to be the only cause. Chronic pain, repeated surgery, fear of pain and altered bowel habits can all cause the pelvic floor muscles to remain guarded or tense. The encouraging part is that pelvic floor muscle coordination can often be retrained with appropriate physiotherapy.
Next Steps
I would recommend a proper assessment by a pelvic-floor physiotherapist, preferably along with your colorectal surgeon/gastroenterologist. Treatment may include diaphragmatic breathing, pelvic-floor relaxation/down-training, bowel and toileting posture training, gentle mobility and, when appropriate, biofeedback. Avoid starting Kegel/strengthening exercises on your own because an already overactive pelvic floor may require relaxation and coordination rather than further strengthening. Your daily laxative use and diarrhoea should also be reviewed by your treating doctor.
Health Tips
Try to sit comfortably and fully supported while passing urine rather than hovering over the toilet. Avoid straining during bowel movements and don't repeatedly force the pelvic floor to relax. Considering your history of multiple surgeries, persistent pain and significant weight loss/weakness, physiotherapy should follow a detailed medical and pelvic-floor assessment rather than self-treatment. If another surgery has been advised and you are uncertain, taking a second opinion from a colorectal specialist before proceeding is reasonable.