Firstly: 

There are many saheeh ahaadeeth which show that anal intercourse is haraam, such as the following: 

1 – It was narrated from Abu Hurayrah (may Allaah be pleased with him) that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “The one who has intercourse with his wife in her back passage has disavowed himself of that which was revealed to Muhammad (peace and blessings of Allaah be upon him).” Narrated by Abu Dawood (3904); classed as saheeh by al-Albaani in Saheeh Abi Dawood. 

2 – It was narrated that Ibn ‘Abbaas (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Allaah will not look at a man who has intercourse with a woman in her back passage.” Narrated by al-Tirmidhi (1165); classed as saheeh by Ibn Daqeeq al-‘Eid in al-Ilmaam (2/660) and by al-Albaani in Saheeh al-Tirmidhi. 

3 – It was narrated that Khuzaymah ibn Thaabit (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Allaah is not too shy to tell the truth” three times. “Do not have intercourse with women in their back passages.” Narrated by Ibn Maajah (1924); classed as saheeh by al-Albaani in Saheeh Ibn Maajah. 

And there are many similar ahaadeeth. Al-Tahhaawi (may Allaah have mercy on him) said in Sharh Ma’aani al-Athaar (3/43): The reports concerning that reach the level of tawaatur. End quote. 

Hence the views of the scholars are based on these ahaadeeth. 

Al-Maawardi (may Allaah have mercy on him) said in al-Haawi (9/319): 

Because that is the consensus of the Sahaabah. It was narrated from ‘Ali ibn Abi Taalib, ‘Abd-Allaah ibn ‘Abbaas, Ibn Mas’ood and Abu’l-Darda’. End quote. 

It says in al-Mughni (7/32): 

It is not permissible to have intercourse with one’s wife in her back passage according to the majority of scholars, including ‘Ali, ‘Abd-Allaah, Abu’l-Darda’, Ibn ‘Abbaas, ‘Abd-Allaah ibn ‘Amr and Abu Hurayrah. This was also the view of Sa’eed ibn al-Musayyab, Abu Bakr ibn ‘Abd al-Rahmaan, Mujaahid, ‘Ikrimah, al-Shaafa’i, ashaab al-ra’y and Ibn al-Mundhir.   

We have discussed this in some detail previously on this site; please see the answers to questions no. 1103 and 52803. 

Secondly: 

Some people imagine that it is permissible to have intercourse with one’s wife in her back passage. They understand from the verse (interpretation of the meaning): “Your wives are a tilth for you, so go to your tilth when or how you will” [al-Baqarah 2:223] that Allaah has permitted everything in this verse, even intercourse in the back passage. This misinterpretation is reinforced for them when they read the hadeeth narrated by al-Bukhaari in his Saheeh – and perhaps this is the hadeeth referred to by the questioner – in which it says: It was narrated that Jaabir (may Allaah be pleased with him) said: The Jews used to say that if (the man) had intercourse from behind, the child would be born with a squint. Then the verse “Your wives are a tilth for you, so go to your tilth when or how you will” [al-Baqarah 2:223] was revealed.  

But this is a misunderstanding of the verse. Allaah says “so go to your tilth when or how you will” which means that all variations of intercourse are permitted, so long as it is in the place of tilth, i.e., the vagina, not the back passage.  So it is permissible for a man to have intercourse with his wife from behind or from in front or lying on their sides so long as it is in the place of tilth and not the back passage. 

The evidence for that is Muslim’s report (1435) of the hadeeth of Jaabir quoted above about the reason for the revelation of this verse, in which it says: If he wishes, when she is lying on her front and if he wishes when she is not lying on her front, so long as that is in only one opening. 

In Abu Dawood’s report of the same hadeeth (2163) it says:  It was narrated that Muhammad ibn al-Munkadir said: I heard Jaabir say: The Jews say that if a man has intercourse with his wife in her vagina from behind, the child will have a squint. Then Allaah revealed the words (interpretation of the meaning): “Your wives are a tilth for you, so go to your tilth when or how you will” [al-Baqarah 2:223]. 

In Sunan al-Tirmidhi (2980) in a report which he classed as hasan, it was narrated that Ibn ‘Abbaas (may Allaah be pleased with him) said: ‘Umar came to the Messenger of Allaah (peace and blessings of Allaah be upon him) and said: O Messenger of Allaah, I am doomed! He said: “Why are you doomed?” He said: I changed my direction last night. The Messenger of Allaah (peace and blessings of Allaah be upon him) did not say anything. Then this verse was revealed to the Messenger of Allaah (peace and blessings of Allaah be upon him) (interpretation of the meaning): “Your wives are a tilth for you, so go to your tilth when or how you will” [al-Baqarah 2:223]. So approach from the front or the back, but avoid the back passage and the time of menses. Classed as hasan by al-Albaani in Saheeh al-Tirmidhi. 

These ahaadeeth and reports explain what is meant by the verse. So it is not permissible for the Muslim to go beyond that and understand it in ways that are not indicated by the reports or by linguistic usage. 

Ibn al-Qayyim (may Allaah have mercy on him) said in Zaad al-Ma’aad (4/261): 

The verse indicates that it is haraam to have intercourse with her in her back passage for two reasons. The first is that it is permitted to have intercourse with her in the tilth, which is the place of birth, and not in the anus which is the place of filth. The place of tilth is what is referred to in the verse “then go in unto them as Allaah has ordained for you”. [al-Baqarah 2:222]. 

The second reason is that Allaah says “when or how you will” i.e., however you wish, from the front or from the back. Ibn ‘Abbaas said: “go to your tilth” means the vagina. End quote. 

Thirdly: 

Perhaps the question is also referring to what al-Bukhaari narrated from Naafi’ from Ibn ‘Umar (may Allaah be pleased with him): “so go to your tilth when or how you will”; he said: “He may approach her from …” 

Ibn Hajar said in Fath al-Baari (8/189): 

This is how it appears in all the texts. It does not mention what comes after the word “from”. End quote.  

And he quoted what is mentioned in some reports elsewhere than in Saheeh al-Bukhaari, that Ibn ‘Umar said:  He may approach her in her back passage. 

But the scholars answered that in two ways: 

1 – That it was a mistake on the part of some of those who narrated it from Ibn ‘Umar, and they understood from it that it was permissible to have intercourse in the back passage, when in fact he was narrating that it is permissible to have intercourse with one's wife in her vagina from behind, based on what is mentioned in saheeh reports from him that he regarded it as haraam to have intercourse with one’s wife in her back passage. And al-Nasaa’i narrated in al-Sunan al-Kubra (5/315) with a saheeh isnaad that Ibn ‘Umar was asked about that and he said: Would a Muslim do that?! 

Ibn al-Qayyim (may Allaah have mercy on him) said in Tahdheeb al-Sunan (2/146): 

It is narrated in a saheeh report that he interpreted the verse as referring to intercourse in the vagina coming from the back, which is what was narrated from Naafi’. Those who thought that Naafi’ improved of intercourse in the back passage are gravely mistaken; rather what he meant was having intercourse from the back in the vagina. Thus they were confused when they thought that when he said “from the back” he meant the back passage; but what he meant by that was coming from the back  but putting it in the place of intercourse, namely the vagina. Those people were confused when they understood the words of Naafi’ “from the back” as meaning “in the back (passage)”. End quote. 

The second answer is: 

That this was ijtihaad on the part of Ibn ‘Umar (may Allaah be pleased with him) about the meaning of the verse. The Sunnah and the views of all the Sahaabah indicate that it was an incorrect ijtihaad. Abu Dawood (2164) narrated, in a report that was classed as hasan by al-Albaani in Saheeh Abi Dawood, that Ibn ‘Abbaas said: 

Ibn ‘Umar – may Allaah forgive him – imagined, and this was a tribe of the Ansaar who had been idol-worshippers, along with this tribe of the Jews, who were people of the Book, and thought that they (the Jews) were superior to them in knowledge; they used to follow their examples in many of their deeds.. The people of the Book did not have intercourse with their wives except on their sides, and that was most concealing for the woman. This tribe of the Ansaar had adopted that from them. And this tribe of Quraysh used to make the woman lie in whatever position they wanted and enjoy them in various ways. When the Muhaajiroon came to Madeenah, one of their men married a woman of the Ansaar, and he went to do that with her but she objected and said: We have intercourse lying on our sides, so do that or keep away from me. Their problem got worse until news of that reached the Messenger of Allaah (peace and blessings of Allaah be upon him) and Allaah revealed the words (interpretation of the meaning): “Your wives are a tilth for you, so go to your tilth when or how you will” [al-Baqarah 2:223]., i.e., from the front or the back or lying, meaning the place of birth. 

This could support the reports that Ibn ‘Umar used to say that it was permissible to have intercourse in the back passage, but then perhaps he came back to the correct view, after Ibn ‘Abbaas or someone else explained to him the reason why this verse was revealed and what its correct meaning was. Hence it is proven – as stated above – that he said that it was haraam, and he said: Would a Muslim do that?! 

To conclude: Islam forbids this action, and there is nothing to indicate that it is permissible. The one who thinks that there is anything in the Qur’aan and Sunnah to indicate that is mistaken. 

And Allaah knows best.