Guaifenex and twice daily

I've got sinusitis (sinus infection) and was prescribed Guaifenex PSE 120 TAB Ethex. Taken twice daily. So far I've had 3 doses, got to take one in a few hours soon. Every time I take it, anywhere within 15 (maybe 30) minutes - a few hours, I get severe abdominal cramping, and sometimes bloating. I thought maybe it's just that I'm not eating enough and there's air pockets in my system that's causing the cramping. But it only happens when I take the meds...
Is abdominal cramping (like a bad menstrual cramp) normal???
Plus I do feel like it is harder to sleep, and at times have felt feverish, or like I'm just burning up, that the room is so hot.
Anyone experiencing any "sexual" side-effects from the drug?

My daughter has been sick since October for various ailments. She has asthma (no acute attacks), allergies and asthma. She was hospitalized once for pancreatitis and had strep a week later. She was left with fatigue and, after a while experienced pronounced urinary symptoms. Doctor diagnosed "urine retention" and took her off her Zertec. She has also had problems with constipation and headaches. Last week she was tested out the ying yang for nine things including brain tumor and Celiac's disease. After reading this website, I'm thinking that maybe she just needs to go off the guafinex he's been taking twice daily on the advice of her allergist.

I started having severe cold symptoms on Weds night... finally decided enough was enough and went to the walk in clinic for a really bad sore throat. Was told the sore throat was because of the nasal drip I was having... I got prescribed Guaifenex and I've been sick since half an hour after taking the meds. I tried waking early, sleeping all day, eating all day even though I was NOT hungry... last night I spent 4 hours sitting on the tub across from the toilet having stomach convulsions and puking up small amounts of red stuff... now I realise it was blood. I haven't slept since Friday night either... the most I can get in is a 20 minute nap. I'm actually lucky because the sticker on the pill bottle says take twice daily and I've only been taking it once a day and feeling like this. I was driving down a SMOOTH HIGHWAY (4 lanes!) today and got so carsick I had to pull over on and vomit... I also have had NO VOICE for 2 days... nothing more frustrating! I have to say my sore throat is pretty much gone, whats left is from me straining to yell at the dog to come in... this drug made me MISERABLE... I am going back tomorrow to give that doctor a talking to... and I expect a drug that isn't going to make me think I'm DIEING... (I actually considered going to the hospital because I felt I was having a seizure).