I first felt ill 5 days after taking Terbinafine 250mg tablets for a fungal nail infection. I had awful stomach cramps and diarrhoea but it only lasted a day. Took a further 5 weeks of Terbinafibe, then started getting cramps, back ache and the shits again. I stopped taking Terbinafine a week ago but I still have back pain, cramps and the shits (usually only once a day). I am getting worried that it wasn't the medication? Shouldn't the side effects have worn off by now? I'm 48 and also perimenopausal.