loss of apetite - ibs

i haven't posted this as the main topic because i had problem with the registration process...anyway the main thing that is bothering in my ibs symptoms lately is the lack of apetite and the 'i can go without eating' for days, before it was the 'i can go without bm ' for days now that i am able to have a bm, i lost the urge to eat, at times i eat so as not to upset my parents because they think that i'm not eating in order 'to gain attention' well God only knows it's not true...even if i have energy and look well without eating, i feel awful bloating inside, i have also muscle pain accompanied to ibs which is normal with ibs but i never read there is lack of apetite accompanied to it although some websites list 'lack of apetite' as a symptom, of bad ibs? ! i had many tests, including gyn tests because my periods were light, the transvaginal ultrasounds (4) and ca125 came clear, then i had colonoscopy, which was clear too, had abdominal scans, all normal and done with sound probes rather than using the 'ray beams like ct -the proceedure is done if abdominal ultrasound is abnormal/ because there are some risks with a ct so they do ultrasound before that if ultrasound is normal then they tell you no further tests required and conclude you have a functional disorder' i also had other blood tests ,like cbc,to check for anemia, esr and cpk for muscle enzymes (muscle pain related) all normal, also had hiv tests and other cbc for tiredness, and all came normal too.., and these were taken month or even less before my loss of appetite started. I'm not tired though lately (i used to take antidipresants probably those made me tired) but i lost the urge to eat probably due to bloating, because it is severe lately, i checked with my doctor called him he said to go back if i start loosing a lot of weight, he said the 'loss of apetite' in my situation is from ibs. i have no fever or blood in stool,...but he told me that i should not be worried about my apetite....! hope ican find somone who can tell me if loss of apetite (a sudden no urge to eat) can be caused by ibs? because sites have different understanding about how ibs works and maybe not all people get the same symptoms. thanks :-(