http://en.wikipedia.org/wiki/Islamic_toilet_etiquette
They have lots of rules too.
yup
No kidding. Here's how to wipe your ass:
"After relieving oneself it is essential to perform Istinjaa (washing with water) of the anus and/or genitals with the left hand and water. The precise mode of performing Istinjaa has also been defined by religious leaders: "At the beginning of Istinja, it is preferable to use toilet paper three times. If Istinjaa is being done on a hot day, then the person should start from the front to the back and then from the back to the front and the third time from the front to the back. If Istinjaa is being done on a cold day, then he should begin from the back to the front. After wiping, he should wash his hand first and then he should cleanse himself with two fingers and three fingers if necessary together with ‘pouring’ water. When using the two fingers, one should keep the middle finger in front and the ring and index finger behind it. After beginning with the fingers in this position, he should bring the ring finger forward and rub with the middle finger and ring finger. Thereafter, he will wipe with the index finger, if necessary. He should continue until all the impurity and smell is removed. The left over water after Istinjaa is paak only if there is no impurity in it." (Mufti Ebrahim Desai) And further: "To wash the orifice with water, even though no filth is stuck to it after relieving oneself, is desirable. If the filth is sticking to it (less than a Dirham or equal to it) then the use of water is 'Sunnah' (optional) and in the case the filth stuck to the orifice is more than a Dirham then its washing with the water is 'Fard'. (obligatory)" Islamic Academy"
Incidentally, I've been to many public restrooms in Arabia. The toilet paper and bidet are always located on the right side of the stall making left-handed use very difficult.